The R.A.P. Project (Reviews of Astro-Ph)
Gravitacionnye volny
(Arhiv Gravitacionnye volny: v.2, 2003,
v.1, 2002-2003)
Authors: Luciano Rezzolla
Comments: 17 pages, CQG, special issue LISA-7
Sliyaniya chernyh dyr - ves'ma aktual'naya tema. Vo-pervyh, v svyazi s tem, chto v kartine ierarhicheskogo formirovaniya galaktik oni proishodyat dostatochno chasto i vazhny dlya ponimaniya galakticheskoi evolyucii. Vo-vtoryh, potomu chto est' nadezhda registrirovat' gravitacionnye volny ot sliyanii. Raschety sliyanii ochen' slozhny i trebuyut mnogo processornogo vremeni. Poetomu est' bol'shaya nuzhda v analiticheskih priblizheniyah. Im-to v osnovnom i posvyashen obzor. Stat'ya na udivlenie dostupno napisana, poetomu sovetuyu ee prosmotret'.
Authors: LIGO Scientific Collaboration
Comments: 6 pages, 1 figre
Avtory privodyat ocherednye verhnie predely, kotorye stanovyatsya vse interesnee i interesnee. Na etot raz rech' idet o poiske po vsemu nebu periodicheskogo signala po dannym LIGO na chastotah 50-1100 Gc. Dlya neitronnyh zvezd s ekvatorial'noi elliptichnost'yu vyshe odnoi millionnoi eto daet predel na rasstoyanie 500 pk. T.e., vplot' do etogo rasstoyaniya net bystrovrashayushihsya neitronnyh zvezd s takim szhatiem.
Authors: Christian D. Ott
Comments: Topical Review, submitted to CQG. 49 pages, 13 figures
Bol'shoi obzor po ozhidaemym gravitacionno-volnovym signalam ot sverhnovyh, svyazannyh so vzryvami massivnyh zvezd.
Authors: M. J. Valtonen et al.
Comments: 14 pages, 3 figures, published in Nature
Lyubopytnyi rezul'tat. V kvazare OJ287 nablyudayutsya periodicheskie vspyshki s periodom 12 let (dve vspyshki za period). Schitaetsya, chto eto svyazano s sushestvovaniem tam dvoinoi chernoi dyry. Yasno, chto, vrashayas' drug vokrug druga, chernye dyry, soglasno OTO, dolzhny izluchat' gravvolny i sblizhat'sya. Poslednyuyu vspyshku (sentyabr' 2007) udalos' predskazat' s tochnost'yu do dnya. Esli by ne bylo gravvoln, to vspyshka proizoshla by na 20 dnei pozzhe.
Model' dlya takogo povedeniya kvazara dvoe iz avtorov obsuzhdaemoi stat'i predlozhili eshe v 1996 godu. Odna iz chernyh dyr dva raza za period peresekaet akkrecionnyi disk vokrug vtoroi, chto i privodit k vspyshkam. Otmechu, chto vse-taki eto lish' odno iz vozmozhnyh ob'yasnenii.
Sam istochnik byl izvesten kak peremennaya zvezda eshe v 19 veke, v 1968 g. on byl identificirovan kak kvazar, tak chto statistika po nablyudeniyam ego vspyshek nabralas' uzhe poryadochnaya. No lish' v proshlom godu dannyh okazalos' dostatochno, chtoby popytat'sya s tochnost'yu do neskol'kih dnei predskazat' sleduyushuyu vspyshku (skazhem, v 1996 godu avtory eshe ne mogli eto sdelat').
Obsudit' v ZhZh-soobshestve
ru_astroph.
Obsudit' na Astroforume v
Nauchnoi panorame.
Authors: Kostas D. Kokkotas
Comments: 22 pages, 2 figures
Horoshii obzor, ohvatyvayushii vse osnovnye voprosy, svyazannye s gravitacionno-volnovoi astronomiei, krome teh, chto svyazany s konkretnymi ustanovkami. Rassmotreny osnovy fiziki gravvoln, istochniki, principy registracii.
Authors: A. T. Deller, J.P.W. Verbiest, S.J. Tingay, M. Bailes
Comments: 11 pages, 1 Figure, submitted to ApJL
Avtory rasskazyvayut o tochnom opredelenii (tochnost' okolo 1%) parallaksa do samogo blizkogo (156 pk) millisekundnogo dvoinogo pul'sara i o tom, chto iz etogo mozhno izvlech'. A izvlech' mozhno nemalo, t.k. dlya takih ob'ektov est' nezavisimye metody opredeleniya rasstoyaniya. Eti nezavisimye metody osnovany na nekotoryh predpolozheniyah, kotorye mozhno proveryat', ispol'zuya tochnyi trigonometricheskii parallaks. Sredi etih prepolozhenii vo-pervyh nado otmetit' postoyanstvo postoyannoi tyagoteniya (n'yutonovoi). I avtory privodyat samyi zhestkii predel na ee proizvodnuyu. Vo-vtoryh, eto neizvestnye massivnye planety na zadvorkah solnechnoi sistemy. I v tret'ih, gravitacionno-volnovoi shum.
Podrobnee ob izmerenii parallaksov pul'sarov s pomosh'yu VLBI sm. arxiv:0808.1598. V chastnosti, tam rasskazyvaetsya ob izmereniyah s submilliarksekundnoi tochnost'yu (tochno opredeleno rasstoyanie do pul'sara na ~2.5 kpc ot nas).
Authors: Stanislav Babak, Mark Hannam, Sascha Husa, Bernard Schutz
Comments: 4 pages, 1 figure
Kosmicheskii lazernyi interferometr LISA budet registrirovat' sliyaniya sverhmassivnyh chernyh dyr. Sprashivaetsya, mozhem li my dostatochno tochno opredelit', v kakoi galaktike proizoshlo sliyanie? Avtory pokazyvayut, chto s uchetom togo, chto my mozhem rasschitat', kak dolzhen vyglyadet' signal (i ot samogo sliyaniya i t.n. "zvon" posle nego), polozhenie mozhno budet opredelyat' dostatochno tochno. Dlya poloviny sistem na z=1 polozhenie budet opredelyat'sya s tochnost'yu 3 uglovye minuty, a dlya 20 procentov - odna uglovaya minuta.
Authors: The LIGO Scientific Collaboration: B. Abbott, et al
Comments: 6 pages, 1 figure
Po rezul'tatam neskol'kih mesyacev nablyudenii komanda LIGO smogla postavit' pryamoi (t.e. poluchennyi po dannym gravvolnovogo detektora) predel na gravizluchenie ot pul'sara v Krabe. I predel etot luchshe kosvennogo predela, poluchennogo po detal'nomu taimingu pul'sara.
S odnoi storony, rezul'tat nulevoi. S drugoi - LIGO eshe raz pokazyvaet, chto predely, ustanavlivaemye etim eksperimentom, luchshe kosvennyh.
Authors: K. Yamamoto et al.
Comments: 8 pages, 9 figures, Amaldi7 proceedings, J. Phys.: Conf. Ser.
CLIO - Cryogenic Laser Interferometer Observatory. Eto prototip yaponskogo proekta LCGT (Large-scale Cryogenic Gravitational Telescope). On nahoditsya v shahte Kamioka, gde budet stroit'sya i LGCT.
CLIO - nebol'shoi proekt, dlina plecha vsego lish' 100 metrov. Sootvetstvenno, ego zadachi ne nauchnye, a tehnicheskie. Poka prototip uspeshno otrabotal pri komnatnoi temperature, a pri rabote v rezhime s ohlazhdeniem vyyavilis' problemy. Obo vsem etom i blizhaishih planah - v stat'e.
Authors: Laura Blecha, Abraham Loeb
Comments: 15 pages, 15 figures
Pri sliyanii chernyh dyr, poluchayushiisya ob'ekt priobretaet lineinyi impul's. Eto nazyvayut gravitacionno-volnovoi raketoi. V poslednie gody effekt nachali uchityvat' v modelyah ierarhicheskogo skuchivaniya galaktik. Avtorov interesuet povedenie uzhe sverhmassivnyh chernyh dyr, to, kak oni budut dvigat'sya, akkrecirovat' i tp. s uchetom togo, chto v rezul'tate sliyanii oni poluchayut dostatochno vysokie (sotni km v sek) skorosti.
Pri skorosti otdachi 100 km/s chernaya dyra osyadet obratno v centr galaktiki cherez million let (amplituda "bultyhanii" poryadka 30 pk). Chem vyshe skorost' - tem dol'she budet "boltanie" i bol'she amplituda. Interesno, chto velichina poluchennoi skorosti malo vliyaet na nabor massy chernoi dyroi za vremya "bultyhaniya" v galaktike, t.e. do osedaniya v centr (drugoe delo, chto chem vyshe skorost' - tem dol'she "boltaetsya"). K sozhaleniyu, obnaruzhit' chernye dyry, sil'no smeshennye ot centrov galaktik neprosto, t.k. chem bol'she smeshenie, tem koroche aktivnaya faza kvazara.
Authors: Luca Baiotti, Bruno Giacomazzo, Luciano Rezzolla
Comments: 33 pages, 29 figures, submitted to Phys. Rev. D
Avtory predstavlyayut novyi detal'nyi raschet sliyaniya dvuh neitronnyh zvezd. Predmet osobogo interesa avtorov ? kollaps v chernuyu dyru. V samom dele, obychno summarnaya massa dvuh neitronnyh zvezd prevoshodit predel ustoichivosti otnositel'no kollapsa v chernuyu dyru. Kollaps mozhet proishodit' srazu posle sliyaniya ili zhe s nekotoroi zaderzhkoi. Zaderzhka svyazana s tem, chto bystroe differencial'noe vrashenie mozhet kakoe-to vremya uderzhivat' ob'ekt ot shlopyvaniya.
Raschety takogo processa kraine slozhny, i dazhe predstavlyaemye rezul'taty daleki ot real'noi situacii. Avtory obsuzhdayut, kakovy mogut byt', naprimer, effekty magnitnyh polei, ne uchityvaemye v dannyh modelyah. Krome togo, poka bylo ispol'zovano dostatochno primitivnoe uravnenie sostoyaniya veshestva neitronnyh zvezd.
Authors: Christian Spiering
Comments: 16 pages, 20 figures. To be published in Astronomische Nachrichten
Astroparticle Physics (ya budu ispol'zovat' udachnyi perevod "kosmomikrofizika") zavoevala status samostoyatel'noi discipliny na styke astrofiziki, fiziki elementarnyh chastic (i uskoritel'noi, i kosmicheskih luchei) i kosmologii. Razumeetsya, chasto nevozmozhno (da i ne nuzhno) tochno opredelit' yavlyaetsya li dannaya rabota ili proekt "kosmomikrofizicheskim" ili ego luchshe nazyvat' kak-to inache. Kak by to ni bylo ? Oblast' harakterizuetsya eshe i tem, chto v nei osushestvlyayutsya ochen' dorogie proekty. Poetomu razlichnye agentstva stroyat dolgosrochnye plany. V stat'e daetsya ochen' interesnyi obzor togo, chto planiruet v etoi oblasti Evropa na blizhaishie 10 let.
Osnovnye voprosy, kotorye stavyat pered soboi v dannoi programme uchenye, takovy:
Pervym stoit vopros o prirode temnoi materii. Zdes' osnovnymi kandidatami yavlyayutsya neitralino i aksiony. Chto delaetsya? Vo-pervyh, idut laboratornye eksperimenty po pryamomu detektirovaniyu chastic temnoi materii. V etoi oblasti evropeicy, pozhalui, aktivnee drugih, i planiruetsya prodolzhat' poiski. Vo-vtoryh, est' vozmozhnost' uvidet' chasticy, yavlyayushiesya produktami raspada ili annigilyacii chastic temnoi materii, naprimer, gamma-kvanty. U evropeicev seichas letaet sputnik PAMELA, ot kotorogo mozhno ozhidat' interesnyh rezul'tatov do zapuska bolee moshnogo amerikanskogo AMS. Odnako, pohozhe, chto u PAMELA est' kakie-to trudnosti. V gamma-diapazone u evropeicev est' nebol'shoi sputnik AGILE. Planiruemyi v blizhaishie mesyacy k zapusku amerikanskii GLAST budet namnogo effektivnee. Krome togo, mozhno iskat' produkty raspada s pomosh'yu nazemnyh gamma-teleskopov, i tut s H.E.S.S. i MAGIC evropeicy vperedi planety vsei. Evropeiskie plany po postroike bol'shogo morskogo neitrinnogo detektora potihon'ku pretvoryayutsya v zhizn', no ochen' potihon'ku (ob etom sm. nizhe). Nakonec, v tret'ih, koe-chto mogut dat' uskoritel'nye eksperimenty, i zdes', konechno, vse nadezhdy na LHC.
Chto kasaetsya temnoi energii, to tut Evropa ogranichivaetsya standartnymi astronomicheskimi proektami v oblasti nablyudatel'noi kosmologii. Samym vazhnym, navernoe, v blizhaishie 10 let budet zapusk sputnika Planck (oktyabr' 2008 goda). Krome togo, planiruyutsya obzory v razlichnyh diapazonah spektra, no eto chistaya astronomiya, kotoruyu kosmomikrofizika podderzhivaet moral'no.
Sleduyushim punktom stoit poisk raspada protona. Dlya obnaruzheniya nado stroit' podzemnye detektory tipa SuperKamiokande, tol'ko na poryadok bol'she. Poka idet prorabotka neskol'kih podhodov (mozhno perechislit' neskol'ko nazvanii proektov LENA, GLACIER, MEMPHYS, LAGUNA). Planiruetsya, chto k 2010 godu budet vybran proekt. Odnako, vse eshe mozhet sil'no zamedlit'sya. Stoimost' ustanovki budet poryadka polumilliarda evro. S takimi proektami evropeicy lyubyat tyanut', poskol'ku nuzhno mezhdunarodnaya kooperaciya, a "u vseh svoi problemy". Razumeetsya, takoi detektor budet i prekrasnym neitrinnym detektorom.
Teper' o "lovle neitrino za borodu". Zdes' interesny ne tol'ko eksperimenty tipa morskih detektorov s ob'emom poryadka kubicheskogo kilometra. Vo-pervyh, idut popytki pomerit' massu neitrino v laboratorii po izmereniyu spektra elektronov pri beta-raspade (eksperiment KATRINA v Germanii). Vo-vtoryh, interesny issledovaniya dvoinogo bezneitrinnogo beta-raspada. Oni dolzhny dat' otvet na vopros o tom, yavlyayutsya li neitrino maioranovskimi ili dirakovskimi. Dvoinoi bezneitrinnyi beta-raspad vozmozhen tol'ko, esli neitrino maioranovskie.
Kosmicheskie luchi. Evropa aktivneishim obrazom uchastvuet v proekte Ozhe. Cherez neskol'ko let nachnetsya montazh severnoi chasti ustanovki v SShA (yuzhnaya polnost'yu gotova i rabotaet). V severnoi chasti 45 procentov prinadlezhit Evrope. Hotya chashe govoryat o kosmicheskih luchah sverhvysokih energii, odnako i na men'shih energiyah est' eshe nemalo nereshennyh problem. Dlya ih razresheniya stroyat otdel'nye detektory. Odin iz detektorov stoit v Germanii, i on budet prodolzhat' svoyu rabotu.
Gamma-astronomiya. Evropeicy ne sobirayutsya ostanavlivat'sya na uspehah, dostignutyh gruppami H.E.S.S. i MAGIC. Razrabatyvaetsya proekt gorazdo bolee krupnoi seti nazemnyh gamma-teleskopov. Po vsei vidimosti budet dve seti (severnaya i yuzhnaya) s neskol'ko raznymi parametrami, optimizirovannymi dlya izucheniya galakticheskih istochnikov (yug) i vnegalakticheskih (sever).
Kraine zamanchivo nachat' registrirovat' neitrino vysokih energii. Eto vozmozhno s pomosh'yu kilometrovyh detektorov v vode ili l'du. Poka v Antakrtide idet montazh IceCube, evropeicy testiruyut v Sredizemnom more neskol'ko prototipov vodnyh detektorov. O edinom evropeiskom detektore poka idut peregovory. Rano ili pozdno on navernyaka budet postroen, no kakaya-to konkretnaya informaciya o dizaine i tp. otsutstvuet. Krome togo, obsuzhdayutsya proekty kosvennoi registracii neitrino ochen' vysokih energii po radioizlucheniyu. V kachestve rabochego tela tut mozhet vystupat', naprimer, Luna.
Nakonec, poslednyaya tema svyazana s gravitacionnymi volnami. V Evrope rabotayut VIRGO i GEO600. Apgreid VIRGO pozvolit poluchit' pribor, kotoryi deistvitel'no smozhet imet' priemlemyi temp registracii sliyanii neitronnyh zvezd i chernyh dyr. Planiruyutsya bolee krupnye ustanovki (Einstein Telescope), no yasno, chto dazhe pri optimisticheskom razvitii sobytii ih sooruzhenie ne popadaet v blizhaishie 10 let. Chto kasaetsya kosmicheskih detektorov, to tut ESA sotrudnichaet s NASA v dele sozdaniya LISA. Poka obsuzhdaetsya data zapuska 2018 god. No, skoree vsego, ona budet neskol'ko otodvinuta. V 2010 godu evropeicy dolzhny zapustit' prototip. Esli s nim vse proidet udachno, to, navernoe, poyavitsya real'nyh grafik realizacii bol'shogo osnovnogo proekta.
Itogo. Seichas kosmomikrofizika nahoditsya na etape, kogda mozhno uspet' snyat' slivki. Pravda, trebuetsya stroit' ochen' dorogie i tehnicheski slozhnye ustanovki na zemle, pod zemlei, pod vodoi i v kosmose. V konce stat'i avtor privodit svodku proektov (i summy), kotorye budut realizovyvat'sya v blizhaishie 10 let.
Pohozhe, chto Evropa ne otstaet ot SShA, ili otstaet ne sil'no. Nu na ee vtoroe mesto pokushat'sya vrode by i
nekomu.
Authors: Kristen Menou, Zoltan Haiman, Bence Kocsis
Comments: 8 pages, To appear in "Jean-Pierre Lasota, X-ray binaries, accretion disks and compact stars" New Astronomy Reviews, eds. M.A. Abramowicz and O. Straub (Elsevier, 2008)
Avtory rassmatrivayut vopros o tom, chto novogo my mozhem uznat' blagodarya detektoru LISA s uchetom togo, chto mozhno budet tochno opredelit' iz kakoi galaktiki prishel signal (vozmozhno, chto eto mozhno budet skazat' dazhe do pika vspleska). Stat'ya prezhde vsego interesna ob'yasneniem nekotoryh vozmozhnostei i ih obsuzhdeniem. V chastnosti, mozhno budet ogranichivat' al'ternativnye teorii gravitacii, t.k. mozhn bude opredelyat' zaderzhku mezhdu prihodom fotonnogo i gravitacionnogo signalov. Krome togo, nablyudeniya na LISA dadut nezavisimuyu ocenku rasstoyaniya do galaktik po ih gravitacionno-volnovomu signalu, chto takzhe ochen' interesno.
Authors: Bence Kocsis, Abraham Loeb
Comments: 4 pages, 2 figures, submitted to Physical Review Letters
Krasivyi rezul'tat. Avtory pokazyvayut, chto pri sliyanii dvuh sverhmassivnyh chernyh dyr budut interesnye nablyudatel'nye effekty v elektro-magnitnom izluchenii.
Sverhmassivnye chernye dyry slivayutsya pri sliyaniyah galaktik. Poetomu vokrug dyr ne pusto - mnogo gaza. Sootvetstvenno, budet akkrecionnyi disk. Imenno v diske i budet proishodit' dissipaciya energii gravvoln. Okazyvaetsya, chto hotya volny budut ochen' slabo "raskachivat'" disk, tem ne menee etogo dostatochno, chtoby za nedeli (a to i gody) do polnogo sliyaniya voznikal nablyudaemyi signal. Krome togo, konechno zhe dolzhen byt' signal i ot samogo sliyaniya. Interesno, chto on pridet k nam na neskol'ko chasov (ili dazhe dnei) pozzhe gravitacionnogo signala (poka tam disk perekonvertiruet gravitacionnye volny v elektro-magnitnye).
Tak chto avtory polagayut, chto vo-pervyh, mozhno nadeyat'sya uvidet' slivayushiesya chernye dyry i do LISA (hotya, razumeetsya, LISA tut nichem ne zamenish': uvidet' signal, kosvenno svyazannyi so sliyaniem, sovsem ne tozhe samoe, chto uvidet' sam gravitacionno-volnovoi signal). Vo-vtoryh, uzhe posle zapuska LISA stoit lovit' elektro-magnitnye signaly, sootvetstvuyushie nablyudayushimsya gravitacionno-volnovym.
Authors: The Virgo collaboration
Comments: 26 pages, 10 figures
Privoditsya verhnii predel na gravitacionnyi signal ot gamma-vspleska GRB 050915a.
Authors: Antoine Petiteau et al.
Comments: 22 pages, Physical Review D 77, 023002 (2008) 11
Trenirovat'sya nado na koshkah. Ili na komp'yuternyh modelyah. Poetomu pri razrabotke krupnyh nauchnyh proektov raznye gruppy zanimayutsya roazrabotkoi komp'yuternyh simulyatorov ustanovki. V dannom sluchae rech' idet o kosmicheskom gravitacionno-volnovom detektore LISA.
Programma pozvolyaet rasschityvat' chuvstvitel'nost' detektora i signaly ot istochnikov s izvestnymi svoistvami. Programma nahoditsya v svobodnom dostupe.
Authors: Alexander Dietz, for the LIGO Scientific Collaboration
Comments: 5 pages, 3 figures, contributed talk, submitted to the proceedings of Gamma Ray Bursts 2007, Santa Fe, New Mexico, November 5-9 2007
Opisano, kak seichas rabotayut detektory LIGO, a takzhe, kak v dannyh etih detektorov iskali signaly v momenty, opredelyaemye nablyudeniyami gamma-vspleskov. Nichego ne naideno, no predely uzhe ves'ma interesnye. V osnovnom rech' idet o predele na korotkii vsplesk GRB 070201, kotoryi proeciruetsya na M31. Esli mestom vspleska i v samom dele byla Tumannost' Andromedy, to LIGO absolyutno tochno isklyuchaet, chto vspyshka byla porozhedna sliyaniem kompaktnyh ob'ektov.
Authors: Zachariah B. Etienne et al.
Comments: 22 pages, 14 figures, submitted to Phys.Rev.D
Avtory predstavlyayut rezul'taty chislennogo modelirovaniya sliyaniya chernoi dyry i neitronnoi zvezdy, poluchennye s pomosh'yu novogo koda. Napomnyu, chto takie sobytiya vo-pervyh, sovershenno tochno yavlyayutsya moshneishimi istochnikami gravitacionnyh voln (i, skoree vsego, LIGO pervymi uvidit imenno ih), a vo-vtoryh, kakoe-to vremya takie sobytiya obsuzhdalis' kak istochniki korotkih gamma-vspleskov.
Rezul'taty podtverzhdayut, chto gamma-vsplesk sdelat' trudno, t.k. pochti vse veshestvo neitronnoi zvezdy srazu provalivaetsya v dyru, i lish' zhalkie procenty idut na obrazovanie diska. Razumeetsya, avtory rasschityvayut formu gravimpul'sa. Sravnenie rezul'tatov raschetov s dannymi o budushih "otlovlennyh" vspleskah gravizlucheniya pozvolit dat' vazhnye ogranicheniya na uravnenie sostoyaniya neitronnyh zvezd.
Authors: LIGO Scientific Collaboration
Comments: 6 pages, 1 figre
Avtory privodyat ocherednye verhnie predely, kotorye stanovyatsya vse interesnee i interesnee. Na etot raz rech' idet o poiske po vsemu nebu periodicheskogo signala po dannym LIGO na chastotah 50-1100 Gc. Dlya neitronnyh zvezd s ekvatorial'noi elliptichnost'yu vyshe odnoi millionnoi eto daet predel na rasstoyanie 500 pk. T.e., vplot' do etogo rasstoyaniya net bystrovrashayushihsya neitronnyh zvezd s takim szhatiem.
Authors: Scott A. Hughes
Comments: 8 pages, 2 figures. For the Proceedings of the 7th Edoardo Amaldi Conference on Gravitational Waves (to be published by Classical and Quantum Gravity)
Ocherednoi nebol'shoi obzor po istochnikam gravitacionnyh voln, kotorye smozhet uvidet' kosmicheskii lazernyi interferometr LISA. Osnovnyh tipov istochnikov dva: eto dvoinye sverhmassivnye chernye dyry i obychnye chernye dyry v pare so svverhmassivnymi. Dlya pervyh mozhno ozhidat' tempa registracii poryadka desyatkov v god. Dlya vtoryh - sotni v god.
Obzor, na moi vzglyad, orientirovan na fizikov.
Authors: C. H. Lenzi et al.
Comments: 8 pages and 3 figures
Sushestvuyut raznye tipy detektorov gravitacionnyh voln. Krome izvestnyh lazernyh interferometrov est' eshe i sfericheskie detektory. Odin iz nih - SCHENBERG - skoro nachnet svoyu rabotu. Sobstvenno, detektor uzhe postroen i idut testy.
V stat'e avtory rasskazyvayut, kakie astrofizicheskie rezul'taty mogut byt' polucheny s pomosh'yu novogo pribora.
Authors: Frans Pretorius
Comments: 42 pages, 7 Figures. The "final version" of this Lecture Note will appear in the book: "Relativistic Objects in Compact Binaries: From Birth to Coalescence" Editor: Colpi et al. Pulisher: Springer Verlag, Canopus Publishing Limited
Bol'shoi obzor-lekciya po sliyaniyam chernyh dyr. Rech' idet o teorii, ne o nablyudeniyah. Odnako chast' lekcii budet vpolne dostupna nespecialistam.
Authors: LIGO Scientific Collaboration: B. Abbott, et al
Comments: 39 pages, 41 figures
Privedeny dannye obrabotki ocherednogo (chetvertogo) otrezka nauchnoi raboty gravitacionno-volnovoi antenny LIGO. Eto byl dostatochno korotkii progon - okolo mesyaca - v nachale 2005 goda. No vazhno ponimat', chto obrabotka dannyh zanimaet ochen' bol'shoe vremya!
Avtory obsuzhdayut poiski periodicheskogo signala. Nichego ne naideno, no predely (osobenno dlya nekotoryh uchastkov nebesnoi sfery) stanovyatsya uzhe interesnymi.
Authors: Craig J. Hogan
Comments: 10 pages, LaTeX, to appear in "Frontiers of Astrophysics: A Celebration of NRAO's 50th Anniversary", eds. A.H.Bridle, J.J.Condon and G.C.Hunt
Avtor rassmatrivaet, kakie vozmozhnosti v issledovanii vselennoi otkroyutsya pered nami v blizhaishie desyatiletiya za schet pryamoi registracii gravitacionnyh voln.
Authors: LIGO Scientific Collaboration
Comments: 23 pages, 10 figures, 14 tables; to be submitted to Phys. Rev. D
Po dannym treh etapov nauchnoi raboty LIGO postavleny verhnie predely na gravitacionnoe izluchenie ot 39 gamma-vspleskov.
Authors: L. P. Grishchuk
Comments: 43 pages including 9 figures, based on an invited lecture at the first J.A.Wheeler School on Astrophysical Relativity, June 2006
Lekciya posvyashena perspektivam obnaruzheniya effektov vozdeistviya reliktovyh (kosmologicheskih) gravitacionnyh voln na fonovoe mikrovolnovoe (t.e. reliktovoe) izluchenie). Po mneniyu avtora uzhe sleduyushee pokolenie eksperimentov (Planck i dr.) smozhet dat' polozhitel'nyi rezul'tat.
Authors: The LIGO Scientific Collaboration
Comments: 11 pages, 9 figures, 2 tables
Predstavleny rezul'taty analiza nablyudenii LIGO po gravitacionno-volnovomu fonu. Sushestvenno, chto rezul'taty polucheny bez predpolozheniya ob izotropii fonovogo izlucheniya. T.o., udalos' postroit' karty verhnih predelov, a ne prosto dat' odno chislo, harakterizuyushee predel "po vsemu nebu".
Authors: Eric Gourgoulhon
Comments: Lectures given at the General Relativity Trimester held in the Institut Henri Poincare (Paris, Sept.-Dec. 2006) and at the VII Mexican School on Gravitation and Mathematical Physics (Playa del Carmen, Mexico, 26. Nov. - 2 Dec. 2006), 220 pages, 25 figures.
Fakticheski, eto kniga, posvyashennaya ochen' populyarnoi seichas tematike - chislennomu modelirovaniyu effektov OTO. Nikakogo "obshego" interesa rabota ne predstavlyaet, no, po vsei vidimosti, yavlyaetsya polezneishim rukovodstvom dlya teh, kto v samom dele etim zanimaetsya.
Authors: John G. Baker et al.
Comments: 5 pages, 3 figures
Goda tri nazad vozrodilsya interes k t.n. "gravitacionno-volnovoi rakete". Ideya tut v tom, chto pri sliyanii chernyh dyr obrazuyushayasya dyra poluchaet impul's (ili, kak govoryat, "kik" - udar, tolchok, kick). Svyazano eto s nesimmetrichnym izlucheniem gravitacionnyh voln.
V samom nachale svoei stat'i Beiker i dr. otmechayut uspehi v chislennom modelirovanii sliyanii chernyh dyr. Tem ne menee, dlya "shirokoi obshestvennosti" bylo by chrezvychaino udobno, esli by rezul'taty raschetov byli horosho zaapproksimirovanny kakoi-nibud' formuloi (pust' i slozhnoi), ibo inache nezavisimym gruppam (u kotoryh net svoih kodov) nevozmozhno vklyuchat' ucheta effekta gravitacionno-volnovoi rakety v svoi modeli. A effekt vazhen dlya mnogih oblastei astrofiziki. V pervuyu ochered' on sushestvenen pri raschetah rosta galaktik v modeli ierarhicheskogo skuchivaniya.
V svoei stat'e Beiker i dr. pytayutsya dat' takuyu formulu, osnovyvayas' na svoih raschetah, a takzhe na rezul'tatah opublikovannyh raschetov drugih grupp. Formula dana, i po slovam avorov ona approksimiruet rezul'taty s tochnost' luchshe 10 procentov.
Authors: Manuela Campanelli, Carlos O. Lousto, Yosef Zlochower, David Merritt
Comments: 4 pages, 4 figs, revtex4
Napomnyu, chto pri sliyanii dvuh chernyh dyr obrazuyushayasya dyra poluchaet dopolnitel'nuyu skorost' iz-za nesimmetrichnogo izlucheniya gravitacionnyh voln na poslednih stadiyah sliyaniya. Tipichnye skorosti poluchayutsya poryadka 100 km/s. Skorost' zavisit ot otnosheniya mass chernyh dyr, ot orientacii ih osei vrasheniya i ot skorosti vrasheniya. Provesti tochnyi raschet nelegko iz-za trudnosti zadachi, poetomu mnogie detali raspredeleniya skorostei ostayutsya neizvestnymi.
Avtory dannoi stat'i issledovali, kakoi mozhet byt' maksimal'naya skorost', priobretennaya chernoi dyroi za schet effekta gravitacionno-volnovoi rakety. Soglasno ih raschetam maksimal'naya skorost' mozhet dostigat' 4000 km/s!
Authors: The LIGO Scientific Collaboration: B. Abbott, et al, M. Kramer, A. G. Lyne
Comments: 21 pages
LIGO prodolzhaet sbor dannyh. Komanda regulyarno vydaet verhnie predely na gravitacionno-volnovoe izluchenie ot radiopul'sarov (obo vsem etom, kstati, mozhno pochitat' vo vtorom nomere "Vokrug Sveta"). Rastet chislo issledovannyh pul'sarov, i predely stanovyatsya vse luchshe i luchshe. Samyi zhestkii na segodnyashnii den' daet parametr ekvatorial'noi elliptichnosti uzhe na urovne 10-6 (ob opredelenii etogo parametra sm., naprimer, gr-qc/0508096, str. 2 uravnenie 2). Eto uzhe na urovne ozhidaemogo. T.e., po vsei vidimosti, nedalek tot den', kogda poyavitsya i signal. LIGO ili VIRGO pervym ego poimayut - uvidim.
Authors: Masaru Shibata, Koji Uryu
Comments: 14 pages. To appear in a special issue of Classical and Quantum Gravity: New Frontiers in Numerical Relativity
Predstavleny rezul'taty novyh chislennyh raschetov sliyanii sistem, sostoyashih iz neitronnyh zvezd i chernyh dyr. Vazhno, chto avtory nahodyat novye argumenty v pol'zu togo, chto takie sistemy mogut porozhdat' korotkie gamma-vspleski.
Authors: Scott A. Hughes
Comments: 8 pages, 2 figures, for the Proceedings of the Sixth International LISA Symposium
LISA - eto kosmicheskii proekt, prednaznachennyi dlya detektirovaniya gravitacionnyh voln. Izyuminka sostoit v tom, chto instrument smozhet rabotat' na dostatochno nizkih chatsotah. Odnimi iz osnovnyh istochnikov v etom diapazone yavlyayutsya massivnye dvoinye s chernymi dyrami. V stat'e daetsya obzor osnovnyh zadach, stoyashih pered LISA, a takzhe opisyvayutsya ozhidaemye rezul'taty.
Authors: LIGO Scientific Collaboration
Comments: 46 pages, 16 figures
Gravitacionno-volnovoi interferometr LIGO uzhe paru let rabotaet v rezhime nauchnyh nablyudenii. Sozdateli ustanovki postoyanno povyshayut chuvstvitel'nost', odnako poka ona vse ravno nedostatochna dlya obnaruzheniya sliyaniya kompaktnyh ob'ektov. Poetomu iz dannyh izvlekayut tu informaciyu, kotoruyu mozhno izvlech'. V chastnosti, rech' idet o verhnih predelah i urovne fona.
Authors: R N Manchester
Comments: 10 pages, in press ChJAA
Konechno, hochetsya zaregistrirovat' gravitacionnye volny kak mozhno neposredstvennee. Dlya etogo i stroyat lazernye interferometry i tverdotel'nye ustanovki. Odnako nablyudeniya radiopul'sarov pozvolyayut poluchat' dannye o gravitacionnyh volnah pust' i ne stol' neposredstvennym, zato bolee deshevym putem. Vse horosho znayut o tom, chto dvoinye radiopul'sary ispytyvayut izmeneniya orbit za schet izlucheniya gravitacionnyh voln. Est' i drugie effekty, svyazannye s nablyudeniem etih ob'ektov, pozvolyayushie poluchat' informaciyu o gravitacionnyh volnah.
Vazhnym dostoinstvom millisekundnyh radiopul'sarov yavlyaetsya porazitel'naya ustoichivost' ih periodov. Ona sravnima s luchshimi zemnymi atomnymi chasami. Po suti, nablyudeniya neskol'kih takih pul'sarov mogut dat' standart chastoty prevoshodyashii atomnye! Etu osobennost' mozhno ispol'zovat' dlya kosvennogo nablyudeniya garvitacionnyh voln.
Gravitacionnye volny vliyayut na nablyudaemye periody pul'sarov. Imenno na nablyudaemye, t.k. rech' idet ob effekte, svyazannym s prohozhdeniem volny cherez nas. Iz-za prohozhdeniya volny period pul'sara budet kazat'sya nam to koroche, to dlinnee. Ideya takogo obnaruzheniya gravitacionnyh voln byla vpervye vyskazana M.V. Sazhinym v 1978 g. Issleduya odin ob'ekt mozhno dat' verhnii predel na fon gravitacionnyh voln (vokrug nas) v opredelennom diapazone chastot. Prichem, pul'sarnye dannye chuvstvitel'ny k ochen' bol'shim periodam - poryadka vremeni nablyudeniya, t.e. neskol'ko let (sootvetstvenno, chastoty gravvoln ischislyayutsya v dannom sluchae nanogercami). Nablyudeniya za neskol'kimi pul'sarami pozvolyaet (tochnee mozhet pozvolit') zaregistrirovat' etot gravitacionno-volnovoi fon.
Sobstvenno, "pul'sarnaya vremennaya reshetka" (Pulsar Timing Array) eto ne novyi pribor. Sami pul'sary i obrazuyut "reshetku" ili "set'". Nablyudeniya zhe planiruetsya provodit' na uzhe horosho izvestnom 64-metrovom radioteleskope. Hotya, elektronnaya nachinka i programmnoe obespechenie dolzhny byt' dorabotany, chtoby vyiti na neobhodimuyu chuvstvitel'nost'. Takaya neobhodimost' byla prodemonstrirovana v techenie pervogo goda nablyudenii.
O proekte takzhe mozhno pochitat' zdes'.
Authors: C. Rodriguez et al.
Comments: 34 pages, 7 figures, Accepted to The Astrophysical Journal
Otkryta sistema iz dvuh sverhmassivnyh chernyh dyr. Eto ne pervaya takaya sistema, i ya uzhe rasskazyval o nih ranee, dazhe ne raz. Odnako novaya sistema vydelyaetsya svoei kompaktnost'yu. Rasstoyanie mezhdu dyrami vsego 7.3 parseka!
K sozhaleniyu, zhdat' sliyaniya prishlos' by dostatochno dolgo. Esli dyry budut teryat' uglovoi moment tol'ko za schet gravitacionnogo izlucheniya, to do sliyaniya celyh 1018 let. V centrah galaktik mozhno pridumat' neskol'ko sposobov, kak sokratit' eto vremya (naprimer, sistema mozhet sblizhat'sya iz-za dinamicheskogo treniya, ili zhe sistema budet vykidyvat' zvezdy, umen'shaya tem samym orbital'nyi moment).
Vazhno, chto eta dvoinaya mozhet byt' pervoi lastochkoi sredi dvoinyh chernyh dyr s rasstoyaniem mezhdu komponentami poryadka neskol'kih parsek i men'she. Takie sistemy vazhny dlya planiruyushegosya kosmicheskogo interferometra LISA.
Authors: L. Villain
Comments: 19 pages, Proceeding of Cargese School "Astrophysical fluid dynamics" (May 2005) organized by B. Dubrulle and M. Rieutord in honour of J.-P. Zahn and S. Bonazzola
Podrobnyi, ponyatnyi i interesnyi obzor, posvyashennyi neustoichivostyam v neitronnyh zvezdah i rodstvennyh im ob'ektah. Takie neustoichivosti budut privodit' k generacii gravitacionnyh voln. Otsyuda termin "gravitacionno-volnovaya astroseismologiya". Pravda, registraciya takih kolebanii - delo budushego.
Authors: Luigi Stella et al.
Comments: 5 pages, Accepted for publication on ApJ Letters
Ya uzhe pisal nedavno o rabote, svyazannoi s gravitacionnym izlucheniem magnitarov. Vot eshe odna. Zdes' rech' idet ne o fone, a ob izluchenii ot skopleniya v Deve. V samom dele, tam temp rozhdeniya magnitarov dolzhen byt' dostatochno vysok, a avtory pokazyvayut, chto pri nachal'nom pole poryadka 1016.5 Gs gravitacionno-volnovi signal budet dostatochno silen, chtoby istochnik udalos' uvidet' modernizirovannoi versiei LIGO. Nalichie signala svyazano s tem, chto moshnoe magnitnoe pole deformiruet neitronnuyu zvezdu, i ona stanovitsya istochnikom gravitacionnyh voln (zvezda budet nesimmetrichna otnositel'no osi vrasheniya iz-za magnitnoi deformacii, sootvestvenno vozniknet precessiya). Ocenki pokazyvayut, chto temp rozhdeniya magnitarov v skoplenii v Deve dolzhen byt' poryadka shtuki v god. T.o., esli predpolozhenie o bystrom nachal'nom vrashenii magnitarov i o tom, chto pri rozhdenii ih pole dostigaet 1016.5 Gs, verno, to modernizirovannaya ustanovka LIGO budet videt' odin vsplesk v god, chto nemalo. Otmechu, odnako, chto izbytka gamma vspleskov magnitarov ot etogo skopleni galaktik my ne vidim.
Authors: Tania Regimbau, Jos Antonio de Freitas Pacheco
Comments: accepted for publication in A&A 17 pages, 7 figures
Ranee eti avtory uzhe provodili raschety gravitacionno-volnovogo fona, svyazannogo s odinochnymi neitronnymi zvezdami. Delo v tom, chto poskol'ku neitronnye zvezdy slegka nesimmetrichny, oni izluchayut gravitacionnye volny. Izluchayut slabo, no zvezd takih vo vselennoi mnogo. Poetomu summarnyi signal poluchaetsya zametnym, i on mozhet byt' zadetektirovan kak fon. V etoi rabote avtory udelyayut osoboe vnimanie magnitaram. Prichina v tom, chto sil'nye magnitnye polya mogut privodit' k dopolnitel'noi deformacii neitronnoi zvezdy, a takaya zvezda budet sil'nee izluchat'. V proshlyh rabotah etot fakt ignorirovalsya, a zdes' uchten.
Avtory polagayut, chto fon ot magnitarov mozhet v budushem meshat' registracii kosmologicheskih gravitacionnyh voln.
Ot sebya dobavim, chto fon mozhet prihodit' sushestvenno neravnomerno ot raznyh uchastkov neba, t.k. magnitary dolzhny byt' sil'no skoncentrirovany v galaktikah s vysokim tempom zvezdoobrazovaniya. Mozhet byt' etot fakt kak-to pomozhet vychest' magnitarnyi fon.
Authors: Louis J. Rubbo et al.
Comments: See related hands-on activity at physics/0503198. Accepted to The Physics Teacher
Populyarnyi obzor, posvyashennyi gravitacionnym volnam, ih detektoram i istochnikam.
Authors: T. Regimbau et al.
Comments: talk given at the GWDAW9 (Annecy, 2004) to be published in CQG
Privodyatsya ocherednye ocenki tempa sliyaniya dvoinyh neitronnyh zvezd. Raschitany chastoty nablyudenii takih sobytii nazemnymi detektorami (LIGO, VIRGO). V svoih nachal'nyh konfiguraciyah, soglasno avtoram, interferometry ne smogut uvidet' sliyaniya (temp sostavlyaet primerno raz v 125-150 let), zato posle "dovodki" detektory smogut registrirovat' po neskol'ku sliyanii v god.
Zametim, chto eti ocenki menee optimistichny, chem, skazhem, raschety Lipunova i dr.
Authors: Naoki Seto
Comments: 6 pages, 1 figure, to appear in PRD
Avtor pokazyvaet, chto registraciya gravitacionnyh voln ot bystrovrashayushihsya neitronnyh zvezd mozhet pozvolit' poluchit' nezavisimuyu ocenku rasstoyaniya do nih s tochnost'yu poryadka 10 procentov.
Authors: Matthew Pitkin, for the LIGO Scientific Collaboration
Comments: Accepted by CQG for the proceeding of GWDAW9, 7 pages, 2 figures
A vot zdes' est' tol'ko verhnie predely. Komanda LIGO predstavlyaet novye ogranicheniya na potok gravitacionnyh voln ot 28 izvestnyh pul'sarov.
Authors: Fredrick A. Jenet, George B. Hobbs, K.J. Lee, Richard N. Manchester
Comments: 8 pages, Accepted by ApJ Letters
Kak izvestno, radiopul'sary mozhno ispol'zovat' v kachestve nezavisimyh standartov tochnogo vremeni. Krome togo, ih mozhno ispol'zovat' i kak nezavisimye detektory gravitacionnyh voln! Ideya eta ne novaya (ee obsuzhdali i v SSSR, naprimer Mihail Vasil'evich Sazhin, na nego avtory akkuratno ssylayutsya). Tem ne menee, seichas perspektiva registracii fona gravitacionnyh voln vyglyadit gorazdo realistichnee chem 30 let nazad.
Authors: L. P. Grishchuk
Comments: 31 pages including 8 figures; expanded version of a talk at the international conference eldovich-90', Moscow, December 2004; http://hea.iki.rssi.ru/Z-90
Stat'ya predstavlyaet soboi rasshirennuyu versiyu doklada, prochitannogo Leonidom Petrovichem v dekabre proshlogo goda v Moskve. Krome sobstvenno obzora po gravitacionnym volnam v kosmologii v rabote est' i memorial'naya chast', posvyashennaya Ya.B. Zel'dovichu.
Authors: A. Melatos, D. J. B. Payne
Comments: 19 pages, 4 figures, accepted for publication in The Astrophysical Journal
V kachestve istochnika gravitacionnyh voln rassmotrena neitronnaya zvezda "v interesnom polozhenii".
Pri moshnoi akkrecii na neitronnye zvezdy veshestvo sushestvenno izmenyaet strukturu magnitnogo polya. Pole "zaryvaetsya" za schet vypavshego veshestva. Formiruetsya nekotoryi "poyas" na magnitnom ekvatore (veshestvo vypadaet v osnovnom na magnitnye polyusa). V svoyu ochered' magnitnoe pole prepyatstvuet proniknoveniyu chasti veshestva v oblast' magnitnogo ekvatora. T.o. obrazuetsya kucha (gora) veshestva. T.k. magnitnye polyusa vovse ne obyazany sovpadat' s "geograficheskimi" polyusami (t.e. magnitnaya os' ne sovpadaet s os'yu vrasheniya), to zvezda priobretaet kvadrupol'nyi moment, a, sledovatel'no, budet izluchat' gravitacionnye volny.
S odnoi storony, avtory pokazyvayut, chto ih bolee sovershenanya ocenka daet amplitudu gravitacionnyh voln vyshe, chem predskazyvalos' ranee. S drugoi storony, velichina vse ravno slishkom mala, chtoby mozhno bylo rasschityvat' na registraciyu sovremennymi versiyami LIGO i VIRGO.
Authors: C. Palomba
Comments: 31 pages, 17 figures; accepted in MNRAS
Eshe odin primer interesnogo populyacionnogo sinteza odinochnyh neitronnyh zvezd.
Esli neitronnye zvezdy obladayut elliptichnost'yu, to oni budut istochnikami gravitacionnyh voln. Bolee togo, esli sushestvuet podklass neitronnyh zvezd s malen'kim magnitnym polem i zametnoi asimmetriei formy, to ih evolyuciya budet opredelyat'sya izlucheniem gravvoln. Imenno takim ob'ektam i posvyashena stat'ya.
Podcherknem, sushestvovanie takogo podklassa kompaktnyh ob'ektov yavlyaetsya gipotezoi. Po vsei vidimosti vvod v stroi detektora gravitacionnyh voln VIRGO pozvolit ili otkryt' ih, ili nalozhit' sushestvennye ogranicheniya na ih kolichestvo ili parametry.
Authors: The LIGO Scientific Collaboration
Comments: 18 pages, 9 figures and 3 tables
Gamma-vsplesk, nablyudavshiisya 29 marta 2003 goda (GRB030329), byl ochen' yarkim. Poetomu v principe mozhno bylo nadeyat'sya na registraciyu gravitacionno-volnovogo signala. Komanda LIGO provela analiz otklika detektora v moment prihoda gamma-vspleska. Razumeetsya, rezul'tat nulevoi (inache ob etom pisali by vse novostnye lenty mira). Odnako vazhno, chto kachestvo takih verhnih predelov rastet. Znachit, mozhet byt' dozhivem i do real'noi registracii signala.
Authors: Eanna E. Flanagan, Scott A. Hughes
Comments: 47 pages, 3 figures. For special issue of New Journal of Physics, "Spacetime 100 Years Later", edited by Richard Price and Jorge Pullin
Razvernutoe vvedenie v teoriyu gravitacionnyh voln.
2005 god - god fiziki. Svyazano eto v pervuyu ochered' so stoletiem special'noi teorii otnositel'nosti. V svyazi s etim ozhidaetsya mnogo konferencii i sbornikov. Tak chto u vseh zhelayushih budet mnogo vozmozhnostei pochitat' pro gravitaciyu, prostranstvo-vremya & Co.
Authors: A.Buonanno et al.
Comments: 4 pages, 5 figures
Interesno, kak nekotorye rezul'taty mogut ne menyat'sya desyatiletiyami. Odna iz pervyh izvestnyh nam rabot, v kotoroi byl rasschitan gravitacionno-volnovoi fon ot sverhnovyh, byla sdelana v 1987 godu. Sverhnovye vo vsei Vselennoi vspyhivayut neskol'ko raz v sekundu (ot odnogo do neskol'kih desyatkov raz). Kazhdaya sverhnovaya daet impul's gravitacionnyh voln. Razbros ocenok ego moshnosti gorazdo bol'she. Sootvetstvenno, na chastotah nizhe 1 Gc eti impul'sy garantirovanno slivayutsya v nepreryvnyi fon, kotoryi prevyshaet ostal'nye astrofizicheskie i kosmologicheskie gravitacionno-volnovye shumy do chastoty 0.01 Gc. Tak bylo dvadcat' let nazad. Seichas obe neopredelennosti umen'shilis', no vse ravno "ocenki imeyut neopredelennost' v neskol'ko poryadkov velichiny" i po prezhnemu "mozhno nadeyat'sya na ih registraciyu nazemnymi interferometrami".
Authors: D.Fargion
Comments: 6 pages
Nazvanie stat'i otchasti provokacionno. Avtor rassmatrivaet vopros o tom, mogut li gravitacionno-volnovye detektory byt' ispol'zovany dlya srochnogo opovesheniya o krupnyh zemletryaseniyah i cunami. Krome togo rassmotreno izmenenie parametrov vrasheniya Zemli posle krupnyh katastrof.
Authors: Thibault Damour and Alexander Vilenkin
Comments: 16 pages, 6 figures
Kosmicheskie struny (ne putat' s mikroskopicheskimi superstrunami) yavlyayutsya ob'ektami ochen' maloi tolshiny, kosmicheskoi (ili, skoree, kosmologicheskoi protyazhennosti) i sushestvennoi massy. Kosmicheskie struny dvizhutsya ili koleblyutsya (zamknutye struny) s lineinymi skorostyami, blizkimi k svetovym. Pri etom oni izluchayut gravitacionnye volny, vysokochastotnaya chast' spektra kotoryh budet popadat' v diapazon chuvstvitel'nosti nazemnyh (LIGO/VIRGO) i kosmicheskih (LISA) detektorov. (Gladkie uchastki strun izluchayut nizkochastotnye volny, vysokochastotnoe izluchenie dayut kaspy - peregiby i skladki zamknutyh strun.) Krome etogo fon gravitacionnyh voln mozhet byt' obnaruzhen po dolgovremennym nablyudeniyam taiminga pul'sarov.
Drugim istochnikom nizkochastotnyh gravitacionnyh voln mogut byt' molodye i plotnye skopleniya zvezd. Etomu posvyashen miniobzor Simona Portegis Zvarta astro-ph/0410531.
Authors: Florian Dubath et al.
Comments: 4 pages, 2 figs
V zametke idet rech' o novom tipe istochnikov gravitacionnyh voln, kotorye vremya ot vremeni ispuskayut dostatochno korotkie impul'sy gravitacionnyh voln. Podobnymi svoistvami mogut obladat' istochniki myagkih povtornyh gamma-vspleskov (myagkie gamma-repitory =SGR), kotorye, kak segodnya predpolagayut, yavlyayutsya magnetarami - neitronnymi zvezdami so sverhsil'nymi polyami. Moshnost' gravitacionnyh vspyshek mozhet razlichat'sya takzhe sil'no, kak i moshnost' gamma-vspyshek etih ob'ektov: raspredelenie moshnosti vspyshek imeet stepennoi vid dN ~ E-1.6dE, a raspredelenie momentov vspyshek zametno otlichaetsya ot sluchainogo (nekorrelirovannogo). Krome etogo v stat'e rassmotreny voprosy registracii podobnyh vspyshek na sovremennyh gravitacionnyh detektorah.
Authors: The LIGO Scientific Collaboration: B. Abbott, et al, and M. Kramer and A.G. Lyne
Comments: 6 pages, 2 figures
Korotkaya, no vazhnaya zametka.
LIGO rabotaet (vse eshe ne postoyanno i ne na planirovavsheisya chuvstvitel'nosti). Poka stavyatsya verhnie predely, no dazhe eto bol'shoi shag vpered.
Dlya korotkih setov izmerenii, kotorye poka provodyatsya na interferometre, nailuchshimi ob'ektami issledovaniya okazyvayutsya izvestnye radiopul'sary, dlya kotoryh s ochen' vysokoi tochnost'yu izvestno kak polozhenie na nebe, tak i skorost' ih vrasheniya (t.e. chastota ozhidaemogo singala).
Dlya 26 odinochnyh radiopul'sarov polucheny horoshie verhnie predely na potok gravitacionnyh voln. Pochti dlya vseh oni ravny neskol'kim edinicam na 10-24 (amplituda gravitacionnoi volny izmeryaetsya bezrazmernyh edinicah - otnositel'nom izmenenii rasstoyaniya mezhdu svobodnymi telami pri ee prohozhdenii). Dlya chetyreh blizhaishih pul'sarov eti predely uzhe sushestvenno ogranichivayut fantazii teoretikov otnositel'no vozmozhnoi nesferichnosti etih ob'ektov - ona ne mozhet prevyshat' ~5x10-6.
Authors: Leor Barack and Curt Cutler
Comments: 26 pages, 23 figures
Central'nye chernye dyry galaktiki zahvatyvayut zvezdy i kompaktnye ob'ekty (v osnovnom belye karliki). Gravitacionnoe izluchenie etih processov popadaet v diapazon chuvstvitel'nosti kosmicheskogo lazernogo interferometra LISA (milligercy). Amplituda ukazannyh signalov dostatochno velika, chtoby oni byli zaregistrirovany. Odnako, osnovnaya chast' ukazannyh signalov ne budet razreshena na individual'nye zahvaty, t.e. ostanetsya shumom. A lyuboi shum vreden dlya nablyudenii. Mozhno li budet zaregistrirovat' chto-to eshe na fone ukazannogo shuma? Otvet da.
Authors: Scott A. Hughes, Marc Favata, Daniel E. Holz
Comments: 6 pages, 3 figure
V stat'e (eshe raz) opisyvaetsya effekt "gravitacionnoi rakety": na kazhdom orbital'nom oborote na krugovoi orbite dvoinaya sistema ispuskaet gravitacionnye volne nesimmetrichno iz-za togo, chto komponenty sistemy postepenno sblizhayutsya. Etot effekt ochen' slab, krome togo kik, priobretennyi na odnom oborote, kompensiruetsya v nachale sleduyushego. Dannaya kartina narushaetsya na poslednem oborote. V rezul'tate, dvoinye chernye dyry posle sliyaniya priobretayut vpolne zametnuyu prostranstvennuyu skorost', prichem ee velichina ne zavisit ot massy sistemy i mozhet dostigat' desyatkov ili dazhe soten kilometrov v sekundu (no nikogda ne mozhet prevysit' 500 km/s).
Authors: L.P.Grishchuk et al.
Comments: 29 pages, 8 figures
Kazhdoe plecho lazernogo gravitacionnogo detektora sostoit iz dvuh zerkal raznesennyh na rasstoyanie poryadka kilometra. Kolebaniya i peremesheniya zemnoi kory na takom rasstoyanii namnogo prevoshodyat effekt, vyzyvaemyi gravitacionnymi volnami. K schast'yu kolebaniya zemnoi kory proishodyat na bolee nizkih chastotah i sisteme shumopodavleniya, vstroennoi v podvesku zerkal, udaetsya otstroit'sya ot geofizicheskih kolebanii. Odnako posle etogo v sisteme shumopodavleniya okazyvaetsya informaciya o kolebaniyah poverhnosti. Takim obrazom, gravitacionnaya antenna mozhet ispol'zovat'sya ne tol'ko po svoemu pryamomu naznacheniyu, no i kak vysokotochnyi i vysokochuvstvitel'nyi geofizicheskii pribor.
Authors: T.Damour et al.
Comments: 49 pages, 6 figures
Slivayushiesya neitronnye zvezdy (ili chernye dyry) naibolee ponyatnyi i ozhidaemyi istochnik gravitacionnyh voln v diapazone nazemnyh (tipa LIGO) i kosmicheskih (LISA) gravitacionnyh antenn. Obychno predpolagayut, chto ekscentrisitet orbity u takih sistem raven nulyu. Eto vpolne obosnovanno - po mere sblizheniya komponent sistemy ekscentrisitet ee orbity bystro ubyvaet. Dlya slivayushihsya zvezd na strogo krugovyh orbitah rasschitany mnogochislennye shablony deformacii antenn, vyzyvaemyh gravitacionnym signalom.
Odnako, esli ekscentrisitet orbity sistemy okazyvaetsya nedostatochno mal, situaciya rezko uhudshaetsya. Dlya opisaniya podobnoi sistemy trebuyutsya eshe dva dopolnitel'nyh parametra, a chislo shablonov, s kotorymi nado sravnivat' prinimaemyi signal, vozrastaet na poryadki.
V dannoi rabote polucheno analiticheskoe opisanie formy volnovogo signala ot slivayushihsya dvoinyh zvezd s nekrugovoi orbitoi. K sozhaleniyu kachestvo privedennyh v preprinte risunkov ne pozvolyaet ih horosho rassmotret'.
Authors: Gilles Esposito-Farese
Comments: 20 pages, LaTeX 2e, 7 postscript figures, contribution to 10th Marce Grossmann Meeting, 20-26 July 2003, Rio de Janeiro, Brazil
Daetsya obzor ogranichenii, nakladyvaemyh nablyudeniyami dvoinyh radiopul'sarov, na razlichnye teorii gravitacii. Interesno, chto seichas samoe sil'noe ogranichenie daet ne teilorovskii pul'sar, a pul'sar v pare s belym karlikom. Odnako, yasno, chto v samom nedalekom budushem samoe sil'noe ogranichenie budet davat' sistema radiopul'sar+radiopul'sar, stavshaya superotkrytiem proshlogo goda.
Authors: Kei Kotake et al.
Comments: 25 pages, 6 figures, accepted for publication in PRD
Vzryvy sverhnovyh yavlyayutsya odnimi iz vozmozhnyh istochnikov gravitacionnyh voln. Pravda, pri etih vzryvah ne takaya uzh bol'shaya dolya energii uhodit v vide gravvspleka, no tem ne menee. Sovremennye detektory mogli by "pochuvstvovat'" sverhnovuyu v nashei Galaktike. Odnako, chitatel' mozhet pomnit', chto dlya gravdetektorov ochen' vazhno zaranee znat' formu signala (hotya by priblizitel'no), togda ego gorazdo legche vydelit' na fone shumov.
Raschet realistichnyh form signalov ochen' slozhen, t.k. slozhny processy, protekayushie pri vzryve. V etoi rabote avtory pytayutsya v slozhnoi chislennoi modeli uchest' effekty magnitnyh polei i uravneniya sostoyaniya veshestva vzryvayushegosya yadra.
Authors: M. Arnaud-Varvella, M.-C. Angonin, Ph. Tourrenc
Comments: 34 pages, Accepted for publication in General Relativity and Gravitation
Ochen' vazhno nakonec zaregistrirovat' gravitacionno-volnovye signaly! Odnako delo eto ochen' slozhnoe. Poetomu lyudi obsuzhdayut raznye (samye ekzotichnye) idei o tom, kak chislo nablyudaemyh signalov mozhno uvelichit'. Zabavnaya mysl' sostoit v vozmozhnosti uvelicheniya chisla detektiruemyh vspleskov za schet linzirovaniya. V etoi stat'e avtory tshatel'no issledovali etot vopros v primenenii k nazemnym i kosmicheskim interferometram. K sozhaleniyu, vyvody pessimisticheskie: nikakogo ser'eznogo uvelicheniya chisla vspleskov ne poluchaetsya. Esli vas interesuyut tehnicheskie detali i vsyakie podrobnosti - pozhaluista, izuchaite stat'yu.
(Arhiv Gravitacionnye volny: v.2, 2003,
v.1, 2002-2003)
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