The R.A.P. Project (Reviews of Astro-Ph)
Akkreciya
(Arhiv Akkreciya: v.2, 2003,
v.1, 2002-2003)
Authors: Andrei M. Beloborodov
Comments: 20 pages
Giperakreciya na chernye dyry mozhet realizovyvat'sya srazu posle kollapsa ili zhe posle sliyaniya dvuh kompaktnyh ob'ektov. Kak izvestno, imenno v takih sistemah, soglasno sovremennoi kartine, voznikayut gamma-vspleski.
Obzor napisan ochen' ponyatno, poetomu ego mozhno smelo vsem rekomendovat'. Takzhe pro akkreciyu na chernuyu dyru, no tol'ko posle sliyanii, sm. svezhuyu original'nuyu stat'yu arxiv:0810.2535.
Authors: A. Lutovinov, S. Tsygankov
Comments: 12 pages, 8 figures
Daetsya obzor rezul'tatov po nablyudeniyam rentgenovskih pul'sarov na sputnike INTEGRAL. Naibolee interesno opisanie zavisimosti energii ciklotronnoi linii ot svetimosti (eto izmereno dlya treh istochnikov). Takzhe rassmatrivaetsya evolyuciya periodov i zavisimost' doli pul'siruyushego ot razlichnyh parametrov.
Authors: Vincent L. Fish et al.
Comments: 4 pages PDF including 1 color figure, accepted for presentation at the XXIX URSI General Assembly
Izvestno, chto central'naya chernaya dyra nashei Galaktiki - Sgr A* - demonstriruet vspyshechnuyu aktivnost' v raznyh diapazonah. V stat'e avtory govoryat o vozmozhnosti obnaruzhenii struktur, nahodyashihsya sovsem blizko k gorizontu sobytii, po nablyudeniyam na submillimetrovyh volnah s pomosh'yu interferometrov s bol'shoi bazoi. Poka takie interferencionnye sistemy eshe ne zarabotali, no eto delo sovsem nedalekogo budushego.
Authors: Christopher W. Mauche et al.
Comments: 9 pages including 5 color encapsulated postscript figures; LaTeX format, uses aipproc.cls, aip-6s.clo, and aipxfm.sty; submitted for inclusion in the proceedings of "Cool Discs, Hot Flows: The Varying Faces of Accreting Compact Objects," ed. M. Axelsson (New York: AIP)
Avtory chislenno issleduyut akkreciyu iz zvezdnogo vetra na kompaktnyi istochnik v tesnyh dvoinyh sistemah. Osoboe vnimanie udelyaetsya sisteme Vela X-1. Avtory ne tol'ko detal'no schitayut gidrodinamiku, no i akkuratno modeliruyut spektr.
Authors: G. Chartas, C. S. Kochanek, X. Dai, S. Poindexter, G. Garmire
Comments: 20 pages, includes 8 figures, submitted to ApJ
Ne ustayu udivlyat'sya, kakie vozmozhnosti daet gravitacionnoe mikrolinzirovanie dlya izucheniya nerazlichimyh s pomosh'yu sovremennyh priborov ob'ektov. Ideya prosta, prodstav'te sebe linzirovanie dalekogo kvazara: est' kvazar, est' my, a mezhdu nami galaktika, vystupayushaya v roli linzy. No v etoi galaktike est' zvezdy. I oni mogut davat' effekt mikrolinzirovaniya. Istochnikom v dannom sluchae yavlyaetsya akkrecionnyi disk vokrug sverhmassivnoi chernoi dyry v kvazare. V rezul'tate, my mozhem poluchat' ocenki razmera izluchayushei chasti diska. Eto ispol'zovalos' dlya proverki modelei diska (model' Shakury-Syunyaeva horosho podhodit), dlya izucheniya korrelyacii razmera diska s massoi cherynoi dyry i t.d. V ocherednoi stat'ei avtory izuchayut linzirovanie v rentgenovskom diapazone, chto dovol'no netrivial'no. Mozhno ocenit' razmer izluchayushei oblasti. Rezul'tat (menee 6 gravradiusov) nalagaet sushestvennye ogranicheniya na modeli koron diskov v aktivnyh yadrah.
Authors: H.C. Spruit
Comments: 24 pages
Rassmatrivayutsya astrofizicheskie dzhety i rol' magnitnogo polya v ih formirovanii, a takzhe ego vliyaniya na nablyudaemye svoistva. V chastnosti, rol' magnitnogo polya velika v "zapuske" dzheta: energiya gravitacionnogo polya perekachivaetsya v energiyu vrasheniya v osnovanii dzheta, a ta, s pomosh'yu magnitnogo polya, uzhe perehodit v kineticheskuyu energiyu strui.
Sushestvenno, chto Spruitu opyat' udaetsya sochetat' strogoe izlozhenie s ponyatnym opisaniem s pomosh'yu prostyh formul.
Authors: James M. Moran
Comments: 14 pages, 12 figures, accepted and to appear in "Frontiers of Astrophysics - A Celebration of NRAO's 50th Anniversary," ASP Conference Series, eds. Alan H. Bridle, James J. Condon and Gareth C. Hunt
V galaktike NGC 4258 blagodarya nalichiyu mazernyh istochnikov v akkrecionnom diske vokrug chernoi dyry, my mozhem poluchat' horoshie dannye o vnutrennem parseke. Eto dovol'no redkii sluchai, t.k., izuchiv sotni galaktik, drugih podobnyh sistem naideno malo (vsego megamazernyh galaktik izvestno okolo sotni - pyat' procentov ot issledovannyh, - no stol' "kachestvennyh" - 4-5 shtuk. Issledovaniya takih megamazernyh sistem v diske pozvolyaet poluchat' ochen' tochnye ocenki mass chernyh dyr i opredelyat' rasstoyaniya do galaktik.
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: S. Vaughan, P. Uttley
Comments: 13 pages, 6 figures, in "Noise and Fluctuations" Proc. SPIE vol. 6603
Akkreciya na neitronnye zvezdy i chernye dyry idet ne rovnym spokoinym potokom. Est' turbulentnye dvizheniya, razlichnye neustoichivosti i tp. Vse eto otrazhaetsya na krivoi bleska istochnika, na taiminge i td. Razumeetsya, astronomy "oborachivayut" zadachu: po taimingu, po nablyudeniyam fluktuacii svetimosti i drugim menyayushimsya harakteristikam oni pytayutsya uznat' chto-to novoe o processe akkrecii. O nekotoryh novostyah v takih issledovaniyah mozhno uznat' ih obzora.
Sm. takzhe stat'yu arxiv:0802.0376, posvyashennuyu analogichnomu voprosu, no tol'ko isklyuchitel'no dlya sistem s chernymi dyrami.
Authors: Rudy Wijnands
Comments: 6 pages, Conference proceedings from 'A Population Explosion: The Nature and Evolution of X-ray Binaries in Diverse Environments', 28 Oct - 2 Nov, St. Petersburg Beach, FL
Razvitie tehniki nablyudenii v rentgenovskom diapazone pozvolyaet detal'no izuchat' dostatochno slabye istochniki v dvoinyh sistemah so svetimost'yu poryadka 1035 erg/s. Sredi nih est' i sil'no peremennye istochniki, i ob'ekty s dostatochno stabil'noi svetimost'yu. Po-vidimomu, bol'shinstvo yavlyaetsya neitronnymi zvezdami. Nekotorye iz nih mogut yavlyat'sya praroditelyami millisekundnyh radiopul'sarov. Etot poslednii moment delaet takie sistemy osobenno interesnymi. Krome togo, v nekotoryh sluchayah my mozhem poluchat' informaciyu o vnutrennem stroenii neitronnyh zvezd, esli nablyudaetsya teplovoe izluchenie, svyazannoe ne s akkreciei, a s zapasennym teplom i piknoyadernymi reakciyami.
Authors: D. P. Marrone et al.
Comments: Submitted to ApJ. Comments welcome
Kak izvestno, v centre nashei galaktiki nahoditsya sverhmassivnaya chernaya dyra (s massoi neskol'ko millionov solnechnyh). Kak izvestno, dyra nasha ves'ma neaktivna: ee svetimost' mala v sravnenii s eddingtonovskim predelom dlya takoi massy. Kak izvestno, s nei svyazan istochnik Sagittarius A*. Kak izvestno, etot istochnik vspyhivaet. Kak izvestno, prichina vspyshek neizvestna.
Avtoram udalos' otnablyudat' odnu iz vspyshek srazu v chetyreh diapazonah s pomosh'yu pervoklassnyh instrumentov. Mozhno nadeyat'sya, chto eti dannye taki pomogut teoretikam postroit' okonchatel'nuyu model' vspyshek.
Sm. takzhe arxiv:0712.2882, gde "konkuriruyushaya firma" obsuzhdaet tu zhe vspyshku. Etoi gruppe udalos' otnablyudat' ee i na VLA.
Authors: Mitchell C. Begelman, Elena M. Rossi, Philip J. Armitage
Comments: 11 pages, 9 figures, MNRAS submitted. Resubmitted version after referee review
Sushestvuet takaya problema: kak bystro vyrastit' iz zarodyshevyh chernyh dyr sverhmassivnye ob'ekty v centrah galaktik? Delo v tom, chto prosto "napihat'" veshestvo vnutr' dyry za schet akkrecii nel'zya, t.k. pri akkrecii vydelyaetsya energiya, i etot potok izlucheniya ostanovit akkreciyu (tochnee otreguliruet ee v sootvetstvii s t.n. Eddingtonovskim predelom, opredelyaemym massoi chernoi dyry).
Avtory rassmatrivayut akkreciyu na chernuyu dyru iz plotnoi gazovoi obolochki. Eto pohozhe na situaciyu, v kotoroi nachinaetsya rost massy chernyh dyr v centrah molodyh galaktik. Za schet otvoda energii konvekciei, avtoram udaetsya obespechit' dostatochno vysokii rost massy. Tak mozhno dorastit' massu do neskol'kih tysyach solnechnyh za million let. Potom obolochka, v kotoroi idet konvekciya, rasseivaetsya. Eto vazhnyi etap v processe uvelicheniya massy chernyh dyr. Veroyatno, nablyudeniya na kosmicheskom teleskope sleduyushego pokoleniya mogut dat' otvet na vopros realizuetsya li takoi scenarii v deistvitel'nosti.
Authors: Chris Done, Marek Gierlinski, Aya Kubota
Comments: 76 pages, accepted for publication in Astronomy and Astrophysics Reviews
Bol'shoi podrobnyi obzor. Prichinoi dlya ego napisaniya posluzhil rost dannyh po tesnym dvoinym sistemam s kompaktnymi ob'ektami. Blagodarya mnogovolnovym nablyudeniyam - ot radio do gamma - udaetsya poluchat' dannye o povedenii i diskov, i dzhetov. Chto, v svoyu ochered', pozvolyaet stroit' modeli, v kotoryh zavyazana evolyuciya diska i dzheta.
Authors: Shawn Poindexter, et al.
Comments: 5 pages, 4 figures, submitted to ApJ
Po dannym o mikrolinzirovanii na volnah ot 0.4 do 8 mikron udalos' opredelit' razmer diska kvazara HE1104-1805 na raznyh dlinah voln (sm. takzhe sleduyushuyu stat'yu).
Authors: Christopher W. Morgan et al.
Comments: 5 pages, 3 figures, submitted to ApJL
Sovershenno porazitel'noe, s moei tochki zreniya, delo! Udaetsya proshupyvat' (v optike!) akkrecionnye diski kvazarov. Rech' idet o nablyudenie struktur razmerom menee 1016 santimetrov s rasstoyanii bolee 1026 santimetrov. Udaetsya eto blagodarya mikrolinzirovaniyu.
My privykli k tomu, chto mikrolinzirovanie nablyudaetsya u nas v Galaktike ili v ee blizhaishih sputnikah. No, okazyvaetsya, ono mozhet srabotat' i v drugih situaciyah.
Nablyudayutsya kvazary, linziruemye galaktikami. Eto sil'noe linzirovanie. No v galaktikah est' zvezdy. I imenno oni mogut davat' effekt mikrolinzirovaniya, pozvolyayushii proshupat' disk kvazara!
Bolee togo, udaetsya pokazat', chto razmer diska kvazara svyazan s massoi chernoi dyry.
Obsudit' v ZhZh-soobshestve
ru_astroph.
Obsudit' na Astroforume v
Nauchnoi panorame.
Authors: A. Ibragimov et al.
Comments: 10 pages, 9 figures and 2 tables, accepted to MNRAS
U izvestnogo kandidata v chernye dyry Cyg X-1 sushestvuet modulyaciya izlucheniya s periodom okolo 150 dnei. Eto mnogo bol'she orbital'nogo perioda. Blagodarya novym dannym avtory poluchili vozmozhnost' dostatochno podrobno issledovat' etu peremennost'. Veroyatnee vsego, my imeem delo s precessiei akkrecionnogo diska. Takoe yavlenie nablyudaetsya i u drugoi izvestnoi sistemy - SS 433. Voobshe, sistemy ochen' pohozhi! Tol'ko rezhimy akkrecii raznye.
Authors: T.P. Roberts
Comments: Invited talk at the 5th Stromlo Symposium. 10 pages, 4 figures. Accepted for publication in Astrophysics & Space Science
Nebol'shoi obzor po rentgenovskim nablyudeniyam UMI. Razumeetsya, avtor obsuzhdaet obe gipotezy o prirode etih istochnikov (chernye dyry promezhutochnyh mass ili zhe obychnye "zvezdnye" chernye dyry), no obzor vse-taki imenno chto nablyudatel'nyi, i v etom ego dostoinstvo. Ne zashishaya ni odnu iz gipotez, avtor izlagaet osnovnye fakty i rassmatrivaet, kak oni ukladyvayutsya (ili ne ukladyvayutsya) v ramki modelei.
Authors: Frederick K. Lamb
Comments: 30 pages, 8 figures, published in "From X-Ray Binaries to Gamma-ray Bursts", proceedings of a symposium held in memory of Jan van Paradijs 6-9 June 2001, eds. E.P.J. van den Heuvel, L. Kaper, E. Roi, & R.A.M.J. Wijers
QPO - kvaziperiodicheskie oscillyacii. Yavlenie sostoit v tom, chto v akkreciruyushih istochnikah nablyudaetsya peremennost' na nekotoryh zarakternyh chastotah, no chastota "plyvet". T.e., eto ne pul'sarnaya chastota, a chto-to menee regulyarnoe. Chto - do konca ne yasno. Sushestvuet dostatochno mnogo modelei. Est' nadezhda, chto pravil'no ponimanie prirody QPO privedet k tomu, chto my poluchim novyi kanal informacii o neitronnyh zvezdah i chernyh dyrah.
Vtoroi obzor Freda Lemba neskol'ko peresekaetsya s QPOshnym i posvyashen akkrecii na neitronnye zvezdy v malomassivnyh dvoinyh sistemah.
Authors: Igor V. Igumenshchev
Comments: 31 pages, 7 figures attached in jpg-format; to appear in ApJ
Teoriya akkrecii razvivaetsya uzhe dostatochno davno. Tem ne menee, dazhe dlya dostatochno prostyh techenii ne dostignuto polnoe ponimanie. Kak yasno iz nazvaniya stat'i, v nei providitsya chislennoe issledovanie trehmernoi sfericheski-simmetrichnoi akkrecii s uchetom magnitnyh polei.
Kak i v bolee rannih issledovaniyah (v tom chisle i samogo avtora stat'i) temp akkrecii konechno zhe men'she, chem v sluchae klassicheskoi akkrecii Bondi. Vazhnym novym vyvodom yavlyaetsya nevozmozhnost' ustanovleniya stacionarnogo sverhzvukovogo sfericheski-simmetrichnogo techeniya pri nalichii melkomasshtabnyh magnitnyh polei.
Authors: Sergei Fabrika
Comments: 100 pages, 19 figures; Astrophysics and Space Physics Reviews (2004), 12, pp. 1-153
Sergei Fabrika iz SAO davno i uspeshno zanimaetsya izucheniem sistemy SS433. I vot, napisal o nei celuyu knigu.
Konechno, rech' tam ne tol'ko ob odnom edinstvennom ob'ekte. Mnogie soobrazheniya primenimy i k drugim istochnikam, naprimer k ul'tramoshnym rentgenovskim istochnikam. Sergei schitaet, chto oni yavlyayutsya analogami SS433.
Authors: Andrew King, Rudy Wijnands
Comments: Andrew King, Rudy Wijnands
Prodolzhaem temu rentgenovskih dvoinyh. Poslednie dannye nablyudenii pokazali nalichie ochen' slabyh istochnikov, yavlyayushihsya rentgenovskimi dvoinymi, v kotoryh idet akkreciya. Priroda sistem neyasna. Avtory rassmatrivayut neskol'ko idei. Svyazany oni s akkreciei s ochen' malomassivnogo kompan'ona. Vozmozhno, chto takie sistemy yavlyayutsya reliktami naseleniya III, t.e. ochen' starymi sistemami, v zvezdah kotoryh malo tyazhelyh elementov.
Authors: Catherine Turon et al.
Comments: 6 pages.
V stat'e predstavleny osnovnye napravleniya razvitiya evropeiskih kosmicheskih proektov, svyazannyh s astronomiei.
Nedavno ESA byl ob'yavlen konkurs na proekty, osushestvlenie kotoryh otnositsya
k 2015-2025 gg., a takzhe na chut' bolee dalekuyu perspektivu.
Bylo podano bolee 150 zayavok, iz nih 47 imeyut
pryamoe otnoshenie k astronomii.
Bezuslovno podderzhka proektov osnovana na nekotorom anlize naibolee
perspektivnyh napravlenii. Ih bylo vydeleno tri.
1. Drugie miry i zhizn' vo Vselennoi
a) Ekzoplanety
b) Zhizn'
c) Obrazovanie zvezd i planet
2. Rannyaya Vselennaya
a) Temnaya energiya
b) Inflyaciya
c) Obrazovanie struktur
3. Evolyuciya yarostnoi (violent) Vselennoi
a) Povedenie veshestva v ekstremal'nyh usloviyah
b) Chernye dyry
c) Sverhnovye
Zatem etot spisok byl sveden k chetyrem osnovnym voprosam, na kotorye
dolzhna otvetit' astronomiya v blizhaishie dva desyatiletiya.
1. Kakovy usloviya dlya obrazovaniya planet i poyavleniya zhizni?
2. Kak poyavilas' Solnechnaya sistema?
3. Kakovy fundamental'nye zakony Vselennoi?
4. Kak poyavilas' nablyudaemaya Vselennaya i iz chego ona sdelana?
Pozhalui, krome pervyh dvuh, voprosy slishkom obshie. Tem ne menee, odobrennye proekty dolzhny pomoch' naiti na nih otvety, ili hotya by prodvinut'sya v ih ponimanii.
V blizhaishee vremya prodvizhenie v ponimanii ustroistva Vselennoi svyazyvaetsya s
takimi proektami:
1. Corot (ESA) i Kepler (USA). Eti missii prednaznacheny dlya poiska planet
tipa Zemli.
2. Herschel (ESA) i JWST (USA-ESA-others). Eti moshnye infrakrasnye
observatorii pozvolyat luchshe razobrat'sya v processah obrazovaniya zvezd i
planetnyh sistem.
3. GAIA (ESA) i SIM (USA). Eti astrometricheskie missii, krome vsego prochego,
pomogut rezko uvelichit' chislo izvestnyh planet-gigantov.
V neskol'ko bolee otdalennom budushem evropeiskie astronomy poluchat kosmicheskii interferometr, rabotayushii v IK diapazone. On budet nuzhen dlya detal'nogo issledovaniya planet tipa Zemli. V chastnosti, mozhno budet napryamuyu izuchat' ih atmosfery. Krome togo, budet postroen bol'shoi kosmicheskii infrakrasnyi teleskop.
Posle missii Planck, prdnaznachennoi dlya izucheniya mikrovolnovogo fona (t.e. reliktovogo izlucheniya) budet postroen eshe bolee moshnyi pribor, nuzhnyi dlya detal'nogo issledovaniya polyarizacii relikta. Eto pozvolit ponyat', kakoi byla Vselennaya srazu posle stadii inflyacii.
Nakonec budet postroena novaya rentgenovskaya observatoriya, kotoraya pridet na smenu XMM-Newton. A chut' pozzhe i gamma-observatoriya, kotoraya prizvana zamenit' sputnik INTEGRAL.
Kak vidno, evropeiskuyu astronomiyu zhdet blestyashee budushee.
Authors: Mark R. Krumholz et al.
Comments: Accepted for publication in ApJ; 13 pages, 9 figures, emulateapj
Klassicheskaya formula akkrecii Bondi neprimenima v sluchae sil'no turbulizovannoi sredy. Avtory obsuzhdayut, kak sil'naya sverhzvukovaya turbulentnost' povliyaet na temp akkrecii. Effekty turbulentnosti dostatochno slozhno uchest'. Dazhe vyvody raboty trudno chetko i kratko sformulirovat'. Vozmozhna situaciya, kogda temp budet vyshe, chem formal'no vychislennyi po formule Bondi, vozmozhna i obratnaya situaciya.
Otmechu, chto avtory prenebregali rol'yu magnitnyh polei. Uchest' srazu i turbulentnost' i polya budet ochen' slozhno dazhe v chislennyh raschetah.
Avtory prilagayut svoi raschety k formirovaniyu molodyh zvezd (sm. bolee podrobno stat'yu teh zhe avtorov nizhe - astro-ph/0510412) i akkrecii na zvezdy do stadii glavnoi posledovatel'nosti. Pokazano, chto dlya massivnyh ob'ektov vozmozhno sushestvennoe izmenenie po-sravneniyu s bolee rannimi modelyami. Krome togo, kratko rassmotrena akkreciya na sverhmassivnye chernye dyry v centrah galaktik.
Authors: L. Foschini et al.
Comments: 6 pages, 4 figures, accepted for publication on Advances in Space Research, Special Issue Proceedings of 35th COSPAR (Paris, France, 18-25 July 2004)
Prodolzhayutsya popytki ponyat' prirodu ul'tramoshnyh rentgenovskih istochnikov (UMI).
Sushestvuet neskol'ko modelei, opisyvayushih akkrecionnye diski. Sredi nih i t.n. "hudye" (slim) diski. Avtory prilagayut dannuyu model' v istochniku H-8 v galaktike v Treugol'nike (M33). Po-mneniyu avtorov nablyudeniya horosho opisyvayutsya v ramkah sushestvovaniya tesnoi dvoinoi sistemy s chernoi dyroi obychnoi (zvezdnoi) massy, akkreciruyushei so sverheddingtonovskim (t.e. sverhkriticheskim) tempom.
Authors: M.M. Kaufman Bernado
Comments: PhD Thesis supervised by G.E. Romero and presented at the University of Buenos Aires (UBA) on December 15th, 2004
V dissertacii mikrokvazary (akkreciruyushie dvoinye s relyativistskimi dzhetami) obsuzhdayutsya kak vozmozhnye neotozhdestvlennye istochniki, nablyudavshiesya priborom EGRET.
Authors: Tomaso Belloni
Comments: 8 pages, 3 figures, in "Interacting Binaries: Accretion, Evolution and Outcomes", eds. L. A. Antonelli, et al., Procs. Interacting Binaries Meeting, Cefalu, Italy, June 2004, in press (AIP)
Chernye dyry v tesnyh dvoinyh sistemah nablyudayutsya kak rentgenovskie istochniki blagodarya akkrecii. Nablyudenii pokazali nalichie raznyh rezhimov, otlichayushihsya (s nablyudatel'noi tochki zreniya) po spektral'nym harakteristikam, moshnosti izlucheniya, modulyacii izlucheniya i t.p.
V obzore summiruetsya klassifikaciya sostoyanii istochnikov s chernymi dyrami. Kratko obsuzhdayutsya fizicheskie usloviya v kazhdom iz sostoyanii.
Raspechatyvaya stat'yu bud'te vnimatel'ny! Poslednie 24 stranicy (iz 40) pustye, t.k. bol'shie risunki nel'zya bylo pomestit' v Arhiv iz-za ogranicheniya na ob'em.
Authors: Marina M. Romanova et al.
Comments: 5 pages with 4 figures, LaTeX, macros: emulapj.sty, avi movies are available at http://www.astro.cornell.edu/us-russia/disk_prop.htm; Journal-ref: ApJ Letters, 616, L151-L154, 2004
Chestno govorya, vsegda nravilis' kartinki i fil'my, demonstriruyushie diskovuyu
akkreciyu.
Rassmotren rezhim propellera pri diskovoi akkrecii na zamagnichennuyu zvezdu.
Rezul'taty mogut primenyat'sya kak dlya akkrecii na neitronnye zvezdy i belye
karliki, tak i dlya issledovaniya zvezd tipa T Tel'ca.
Na pervoi serii risunkov pokazano, kak izmenyaetsya konfiguraciya magnitnogo polya. Na levom risunke (T=0, vremya otschityvaetsya v uslovnyh edinicah, sootvetstvuyushih odnomu oborotu s keplerovskoi skorost'yu na rasstoyanii 2.86 radiusa zvezdy) pokazana nachal'naya konfiguraciya polya. Zatem nachinaetsya raschet, i vidno, kak silovye linii formiruyut "magnitnye bashni". V nizhnei chasti dano uvelichennoe izobrazhenie linii vblizi diska dlya T=70.
Na vtoroi serii risunkov prodemonstrirovano, chto nesmotrya na to, chto sistema nahoditsya na stadii propellera, kogda bystrovrashayusheesya magnitnoe pole prepyatstvuet proniknoveniya veshestva na poverhnost' zvezdy, nekotoraya akkreciya tem ne menee vozmozhna. Na srednem risunke otchetlivo vidno eto "proniknovenie".
Authors: Paola D'Alessio (CRyA) et al.
Comments: 7 pages, 1 table
Eto anons novoi versii kataloga fizicheskih modelei akkrecionnyh diskov
s uchetom oblucheniya (irradiacii)
central'noi zvezdoi. Katalog soderzhit okolo 3000
modelei s razlichnymi central'nymi zvezdami, razmerami i naklonom
diskov, raznymi obiliyami pyli i tempami akkrecii. Dlya kazhdoi modeli
privedeny zavisimosti fizicheskih parametrov ot radiusa i sinteticheskie
spektry. Katalog dostupen po sleduyushim adresam:
http://www-cfa.harvard.edu/youngstars/dalessio/ (SShA),
http://www.astrosmo.unam.mx/~dalessio/ (Meksika) i
http://www.laeff.esa.es/models/dalessio/ (Ispaniya).
Authors: Marek A. Abramowicz
Comments: 17 pages, 3 figures
Eshe odin obzor, napisannyi klassikom Marekom Abramovicom, iz pod pera kotorogo vyshel celyi ryad shiroko izvestnyh rabot po akkrecii.
Teoriya sushestvenno sverheddingtonovskoi akkrecii na chernye dyry byla razrabotana v 80-h godah v Varshave gruppoi Bogdana Pachin'skogo v terminah "pol'skih ponchikov": opticheski tolstyh vrashayushihsya potokov so slaboi vyazkost'yu. Drugoi podhod slim-diski byl pozdnee predlozhen Abramovicem i Lasotoi, no on deistvuet tol'ko dlya umerennogo prevysheniya eddingtonovskogo predela.
Authors: Daniel Proga
Comments: 15 pages, 4 figures
V obzore rassmatrivaetsya istechenie veshestva iz akkrecionnogo diska v kataklizmicheskih peremennyh pod deistviem davleniya izlucheniya v liniyah. Rassmatrivaetsya kak chisto gidrodinamicheskii, tak i magnitogidrodinamicheskie mehanizmy. Obsuzhdayutsya fizicheskie principy i ih realizaciya v chislennyh shemah.
Authors: M. van der Klis
Comments: 73 pages, 21 figures, no color to appear in Compact stellar X-ray sources, Lewin & van der Klis (eds), Cambridge University Press
Eshe odna glava iz "Compact stellar X-ray sources".
van der Klis yavlyaetsya, pozhalui, samym krupnym ekspertom po QPO - kvaziperiodicheskim oscillyaciyam, Etot tip peremennosti nablyudaetsya u akkreciruyushih neitronnyh zvezd i chernyh dyr. Po QPO mozhno poluchat' vazhnuyu informaciyu o parametrah sistem.
Authors: Phil Arras, Dean Townsley, Lars Bildsten
Comments: 6 pages, 2 figures.
Pul'sacii akkreciruyushih belyh karlikov, vhodyashih v sostav nekotoryh kataklizmicheskih peremennyh, byli zaregistrirovany dostatochno nedavno (eto slozhnaya nablyudatel'naya zadacha). V principe, po takim kolebaniyam mozhno izuchat' vnutrennyuyu strukturu pul'siruyushih zvezd. No poka v etoi oblasti poluchen tol'ko odin rezul'tat: dlya sistemy GW Lib na osnove izucheniya ee pul'sacii polucheny ocenka massy belogo karlika (MWD=1.05Mo) i massy obolochki akkrecirovannogo veshestva (Menv=0.4x10-4 Mo).
Authors: Milos Milosavljevic, E. S. Phinney
Comments: 4 pages, 2 figures
Sliyaniya dvoinyh (sverh)massivnyh chernyh dyr s massami 105-107 Mo budut s legkost'yu registrirovat'sya kosmicheskim lazernym interferometrom LISA (Laser Interferometer Space Antenna) dazhe s krasnyh smeshenii z=20.
Odnako dannoe gravitacionnoe sobytie ne proidet nezamechennym i v drugih diapazonah: ono budet soprovozhdat'sya elektromagnitnym "poslesvecheniem", voznikayushim po sleduyushei prichine:
- Zadolgo do sliyaniya chernye dyry nachinayut "sgrebat'" okruzhayushii ih gaz, kotoryi v vyazkoi shkale vremeni formiruet disk vokrug (snaruzhi ot) dvoinoi sistemy (circumbinry disc).
- Vnutrennyaya granica diska primerno sovpadaet s tochkoi, gde prilivnye sily ot dvoinoi sistemy sravnivayutsya s deistvuyushimi v diske vyazkimi silami.
- Vnachale vnutrennii krai diska sleduet za chernymi dyrami po mere ih sblizheniya, no na poslednem etape skorost' sblizheniya komponent sistemy rezko vozrastaet i disk ot etogo processa "otstaet".
- Posle sliyaniya obrazuetsya odinochnaya chernaya dyra, okruzhennaya diskom.
- Cherez nekotoroe vremya pod deistviem vyazkih sil vnutrennii krai diska
priblizhaetsya k chernoi dyre i v sisteme voznikaet rentgenovskii istochnik so
svetimost'yu do 1044 erg/s i vremenem zhizni poryadka desyati
let (dlya massy chernoi dyry 106 mass solnca).
Eto i est' "poslesvechenie" slivshihsya chernyh dyr.
Authors: Jean-Pierre Lasota, Noam Soker
Comments: 6 pages
Avtory obrashayut vnimanie na to, chto teplovaya model' formirovaniya dzhetov, razrabotannaya dlya protozvezdnyh ob'ektov okruzhennyh diskom, prekrasno podhodit i dlya kataklizmicheskih peremennyh: dvoinyh zvezd v kotoryh prisutstvuet belyi karlik okruzhennyi akkrecionnym diskom. Primenenie teplovoi modeli k etomu novomu tipu sistem pozvolyaet estestvennym obrazom otvetit' na vopros pochemu u nih otsutstvuyut dzhety. Prichinoi etogo okazyvaetsya otnositel'naya slabost' vliyaniya magnitnyh polei na disk v kataklizmicheskih peremennyh.
Authors: E.R.Zimmerman et al.
V osesimmetrichnom akkrecionnom diske kazhdoe ego kol'co ispuskaet teplovoe chernotel'noe izluchenie. No temperatura izlucheniya u raznyh kolec otlichaetsya. V itoge summarnyi spektr imeet v shirokom intervale chastot stepennoi vid. Do togo, kak v 1969 godu Lindenbell vpervye rasschital spektr akkrecionnogo diska, schitalos', chto stepennoi spektr mozhet proizvodit'sya tol'ko neteplovymi istochnikami izlucheniya. V posledstvii k podobnym istochnikam izlucheniya stal primenyat'sya termin "mul'titemperaturnyi".
V "standartnoi" teorii akkrecionnyh diskov, kotoruyu razrabotali Shakura i Syunyaev, predpolagalos', chto na vnutrennem krae diska vyazkie natyazheniya obrashayutsya v nol'. Segodnya dlya diskov vokrug chernyh dyr chashe primenyaetsya model', v kotoroi k veshestvu na vnutrennem krae diska prilozhen nekotoryi moment sil. Avtory dannoi raboty sravnili dve ukazannye modeli na primere horosho izuchennyh sputnikom RXTE kandidatov v chernye dyry: 4U 1543-47, XTE J1550-564 i GRO J1655-40. Ih vyvod takov: obe modeli horosho opisyvayut nablyudaemye spektry, tol'ko v klassicheskoi modeli radius vnutrennei granicy dolzhen byt' v 2.2 raza men'she. Etot rezul'tat vazhen dlya opredeleniya uglovogo momenta chernyh dyr i tempa akkrecii na nih.
Authors: G.S. Bisnovatyi-Kogan
Comments: 24 pages, 18 figures.
Esli akkreciruyushee veshestvo neset vmorozhennoe v sebya magnitnoe pole, to davlenie polya rastet bystree, chem davlenie samogo veshestva. I esli v nachale pole ne bylo ochen' ochen' slabym, to mozhet nastupit' moment, kogda osnovnuyu rol' v dinamike akkrecii stanut igrat' imenno magnitnye polya. Teoriya dannyh processov otlichaetsya ot togo, chto predskazyvaet kak standartnaya al'fa-model', tak i modeli advekcionnyh diskov.
Shematichnoe izobrazhenie struktury diska s magnitnym polem
V obzore podrobno rassmotreny vse aspekty dannoi teorii.
Authors: Li-Xin Li
Comments: 28 pages, including 11 figures; accepted in PASJ
Rassmotrena model' chernoi dyry, okruzhennoi akkrecionnym diskom, s umerenno sil'noi magnitnoi svyaz'yu, kogda samaya vnutrennyaya chast' akkrecionnogo diska vrashaetsya tverdotel'no iz-za krupnomasshtabnogo magnitnogo polya. Pokazano, chto esli moment vrasheniya chernoi dyry prevoshodit nekotoroe kriticheskoe znacheniya
to energiya vrasheniya chernoi dyry nachinaet vkachivat'sya v disk i mozhet povysit' ego svetimost' na poryadki velichiny.
V protivopolozhnom sluchae (pri a < acr) dvizhenie vnutrennei oblasti diska opredelyaetsya magnitnym polem, a ego vnutrennyaya granica raspolagaetsya na radiuse korotacii (tam, gde Keplerovskaya orbital'naya uglovaya skorost' stanovitsya ravnoi skorosti vrasheniya chernoi dyry). Svetimost' diska v etom sluchae rezko snizhaetsya po sravneniyu so standartnoi (al'fa) model'yu.
Authors: Rohta Takahashi
Comments: 13 pages, 6 figures, accepted in ApJ
Mozhno li opredelit' spinovyi parametr ("skorost' vrasheniya") chernoi dyry prosto glyadya na nee? Da, po forme i polozheniyu ee "teni" na fone yarkogo akkrecionnogo diska ("ten'" - oblast' otkuda k nam ne prihodyat fotony), hotya takoe opredelenie inogda ne daet odnoznachnogo rezul'tata.
Authors: Anthony L. Piro (UCSB), Lars Bildsten (KITP, UCSB)
Comments: 14 pages, 3 pages
Esli u belogo karlika slaboe magnitnoe pole, a akkrecionnyi disk tonkii (tolshina vnutrennego kraya v neskol'ko raz men'she razmera zvezdy), to disk dohodit do poverhnosti zvezdy v oblasti ekvatora vrasheniya. Skorost' veshestva diska tam vyshe, chem skorost' poverhnosti zvezdy. Veshestvo tormozitsya i rastekaetsya po poverhnosti, obrazuya tak nazyvaemyi "pogranichnyi sloi", v kotorom vydelyaetsya prakticheski stol'ko zhe energii, kak vo vsem ostal'nom akkrecionnom diske v celom. Veshestvo rastekaetsya po poverhnosti zvezdy, priblizhayas' k polyusam, ego skorost' i temperatura postepenno sravnivayutsya s parametrami zvezdy.
Etot process vyglyadit takzhe, kak mnogokratno ranee opisannoe obrazovanie pogranichnogo sloya u akkreciruyushei neitronnoi zvezdy so slabym magnitnym polem. Dlya belyh karlikov chislennoe modelirovanie (provedennoe v stat'e) delaetsya, kazhetsya, vpervye.
Authors: T.Nagae et al.
Comments: 8 pages, accepted in Astron. Astroph.
Esli zvezda v tesnoi dvoinoi sisteme ne zapolnyaet polost' Rosha, no blizka k etomu, i, odnovremenno, obladaet moshnym zvezdnym vetrom, to akkreciya mozhet byt' dostatochno moshnoi, a ee fizika - ochen' interesnoi.
V dannoi rabote privedeny rezul'taty trehmernogo gidrodinamicheskogo modelirovaniya, provedennye gruppoi yaponskih issledovatelei. Tehnicheskaya storona (sobstvenno samo chislennoe modelirovanie) v stat'e rassmotrena ochen' kratko, zato mnogo graficheskih illyustracii. Osoboe vnimanie avtory udelyayut voprosu kachestvennomu razlichiyu struktury potokov pri akkrecii iz vetra (sil'noe nedozapolnenie polosti Rosha), pri techenii cherez tochku Lagranzha (polost' Rosha zapolnena) i v promezhutochnyh sluchayah (maloe otklonenie ot polosti Rosha).
Sleva tipichnaya geometriya potoka pri akkrecii iz zvezdnogo vetra, sprava - pri zapolnenii polosti Rosha. |
Authors: C.J. Clarke, J. E. Pringle
Comments: 8 pages, 0 figures, Accepted in MNRAS
Stat'ya, v kotoroi vyazkie Keplerovskie akkrecionnye diski opisyvayutsya v ramkah kineticheskoi teorii. Dostatochno interesno s teoreticheskoi tochki zreniya.
Authors: Sandip K. Chakrabarti
Pervoi rabotoi, otnosyasheisya k dannomu napravleniyu, avtor schitaet vyshedshuyu v 1952 godu nazad stat'yu Bondi (Bondi) o sfericheskoi akkrecii. [50 let etoi stat'e ispolnilos' v 2002, kogda i byl opublikovan dannyi obzor.] S etogo vremeni potok statei ros eksponencial'no i bylo sdelano ochen' mnogo.
Authors: Wlodek Kluzniak, Marek A. Abramowicz, William H. Lee
Comments: 4 pages, presented at X-ray Timing 2003: Rossi and Beyond, Boston, November 2003
QPO - kvaziperiodicheskie oscillyacii. Eto vazhnyi fenomen, nablyudayushiisya v akkreciruyushih tesnyh dvoinyh sistemah s neitronnymi zvezdami i chernymi dyrami. Prichiny vozniknoveniya QPO neyasny. Est' dostatochno mnogo modelei i vse vremya poyavlyayutsya novye (sm. samuyu poslednyuyu v svezhei rabote The MHD Alfven wave oscillation model of kHz Quasi Periodic Oscillation of Accreting X-ray Binaries).
Zdes' zhe avtory rassmatrivayut QPO kak nelineinyi rezonans (sm. takzhe ih stat'yu Resonance in forced oscillations of an accretion disk and kHz QPOs). Poskol'ku yavlenie nablyudaetsya i u sistem s neitronnymi zvezdami, i u sistem s chernymi dyrami, to, polagayut avtory, nado smotret' na to obshee, chto u nih est'. U chernyh dyr net ni poverhnosti, ni magnitnogo polya. Znachit, ostaetsya akkrecionnyi disk. I imenno on igraet klyuchevuyu rol' v ih modeli: QPO - eto rezonansnye kolebaniya akkrecionnogo diska.
V otdel'noi stat'e (astro-ph/0402012) avtory rassmatrivayut QPO v sistemah s chernymi dyrami, nadeyas' s pomosh'yu etogo instrumenta poluchit' otvet o prirode ul'tramoshnyh rentgenovskih istochnikov.
Authors: Raymundo Baptista
Comments: 5 pages, 3 postscript figures, 2 links for animated gif files, coded with AN latex style file. To appear in Astron. Nachrichten
Dlya kataklizmicheskih peremennyh (dvoinye sistemy s belym karlikom) mozhno pytat'sya stroit' izobrazheniya akkrecionnogo diska, esli nablyudayutsya ego zatmeniya vtoroi zvezdoi. Metod predlozhen davno, i davno uzhe primenyaetsya. Ob osnovah metodiki, osnovnyh rezul'tatah i planah kak raz mozhno uznat' iz etogo korotkogo obzora.
A eshe mozhno posmotret' animashki:
http://www.astro.ufsc.br/~bap/anslide1.gif
http://www.astro.ufsc.br/~bap/anslide2.gif
http://www.astro.ufsc.br/~bap/slide0.gif
http://www.astro.ufsc.br/~bap/ipmovie.gif.
Authors: D.K. Galloway et al.
Comments: 10 pages, 4 figures; submitted to ApJ
Glitch - eto sboi perioda vrasheniya. Nablyudayutsya oni u obychnyh radiopul'sarov (naprimer, u pul'sara v Krabe) i nedavno byli otkryty u anomal'nyh rengenovskih pul'sarov. No nikogda glitchi ne nablyudalis' u akkreciruyushih neitronnyh zvezd v tesnyh dvoinyh sistemah.
Pri glitche skachkom menyaetsya period vrasheniya. Menyaetsya na neznachitel'nuyu velichinu. Svyazyvayut eto ili s izmeneniem momenta inercii kory zvezdy, ili s otryvom vihrevyh nitei, kotorye "pricepleny" k kore iznutri.
Avtory etoi raboty privodyat dannye o rezkom (zavedomo menee 10 chasov) izmenenii perioda neitronnoi zvezdy v sisteme KS 1947+300. Eto dvoinaya s Ve-zvezdoi. Period vrasheniya neitronnoi zvezdy 18.7 sekundy. Vvidu slozhnosti povedeniya perioda vrasheniya akkreciruyushih neitronnyh zvezd v dvoinyh sistemah avtory rassmatrivayut razlichnye prichiny skachka perioda. Odnako, po ih mneniyu, glitch - samaya veroyatnaya. Tem ne menee otmetim, chto delo eto poka temnoe. Tem bolee, chto glitch poluchaetsya ochen' netipichnym kak po velichine, tak i po posleduyushei evolyucii vrasheniya neitronnoi zvezdy. V lyubom sluchae, avtoram udalos' uvidet' ochen' interesnoe yavlenie.
Authors: Hideyuki Saio and Ken'ichi Nomoto
Comments: 7 pages, 4 figures
Termoyadernoe gorenie belogo karlika vyzyvaet vzryv sverhnovoi tipa Ia. Nachinaetsya etot process v samyh plotnyh sloyah zvezdy: v ee centre. Eto utverzhdenie sovershenno verno dlya nevrashayushihsya, sfericheski simmetrichnyh karlikov. Ono ostaetsya vernym pri medlennom i umerenno bystrom ih vrashenii. No kogda skorost' vrasheniya na ekvatore stanovitsya sravnimoi s Keplerovoi, situaciya menyaetsya: gorenie mozhet nachat'sya ne v centre zvezdy, a na nekotorom rasstoyanii ot nego.
Krome togo bystro vrashayushiesya belye karliki dol'she ne zagorayutsya. Iz etogo avtory raboty delayut vyvod, chto sliyaniya dvoinyh belyh karlikov ne dolzhny privodit' k sverhnovym Ia (t.e. takie sverhnovye porozhdayutsya iz medlenno vrashayushihsya belyh karlikov v tesnyh sistemah s normal'nymi kompan'onami).
Smotrite, takzhe, stat'yu na svyazannuyu temu "Explosion models for thermonuclear supernovae resulting from different ignition conditions" (astro-ph/0401230).
Authors: D. Maitra, C. D. Bailyn
Comments: 25 pages, 11 figures. Accepted for publication in ApJ
V astronomii pochti vsegda poluchaetsya tak: ishut, gde yarche. Naprimer, esli otkryt novyi tip istochnikov, to kakoi-nibud' odin stanovitsya naibolee izuchennym, "standartnym" i t.d. i t.p. Dlya myagkih rentgenovskih tranzientov (eto malomassivnye rentgenovskie dvoinye s neitronnymi zvezdami) takovoi yavlyaetsya sistema Aql X-1.
Eto dvoinaya s orbital'nym periodom okolo 19 chasov, nahodyashayasya na rasstoyanii 4-7 kpk ot nas. Malomassivnyi komponent - zvezda klassa K, zapolnyayushaya polost' Rosha. Primerno raz v god istochnik vspyhivaet.
Osen'yu 2000 g. vo vremya ocherednoi vspyshki provodilis' sovmestnye nablyudeniya v optike i rentgene (sputnik RXTE). Takie issledovaniya ochen' vazhny, t.k. fizika processov v myagkih rentgenovskih tranzientah ostaetsya do konca neponyatoi.
Authors: Didier Barret
Comments: 12 pages, 9 figures
Na 12 stranicah (vklyuchaya risunki) avtor uspevaet uspeshno upomyanut':
- o vysokom i nizkom (myagkom i zhestkom) sostoyanii akkreciruyushih istochnikov;
- o teplovoi i neteplovoi komptonizacii fotonov;
- ob istochnike myagkih fotonov;
- ob otrazhenii rentgenovskogo izlucheniya ot poverhnosti zvezdy, diska i ih korony;
- o peremennosti izlucheniya - kvaziperiodicheskih oscillyaciyah;
(Arhiv Akkreciya: v.2, 2003,
v.1, 2002-2003)
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