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| 20.12.02. astro-ph za 16 - 20 dekabrya 2002 goda: izbrannye stat'i |
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Teper' my budem starat'sya vydelit' "luchshih iz luchshih".
Authors: Anatoly A. Svidzinsky
Authors: V.S. Beskin
Authors: S. Johansson, V. S. Letokhov Authors: Joseph Silk Commets: 22 pages, Plenary talk at TH-2002, UNESCO, Paris, July 22-26, 2002, to be published in Annales Henri Poincar\'e Dovol'no podrobno (naskol'ko eto vozmozhno v 20-ti stranichnom obzore) so mnozhestvom ssylok opisyvaetsya otkrytie reliktovogo izlucheniya, sootvetstvuyushaya teoriya, a takzhe obsuzhdaetsya razvitie etoi oblasti. Seichas issledovaniya relikta - ochen' goryachaya tema. No nado toropit'sya, na 21-m tehasskom simpoziume (Florenciya, 9-13 dekabrya) bylo vyskazano rezonnoe mnenie, chto posle sputnika Plank potok dannyh po fonovomu izlucheniyu mozhet byt' nadolgo ischerpan.... O polyarizacii reliktovogo izlucheniya sm. stat'i "The large-scale polarization of the microwave background and foreground" astro-ph/0212419, "CMB Polarization at Large Angular Scales: Data Analysis of the POLAR Experiment" astro-ph/0212425.
Authors: H.-Th. Janka et al. Commets: 34 pages; 11 figures. Review for `Core Collapse of Massive Stars'', Ed. C.L. Fryer, Kluwer, Dordrecht Podrobnyi kriticheskii obzor po mehanizmam vspyshek sverhnovyh. Rassmatrivayutsya vzryvy massivnyh zvezd. Zdes' sushestvuet eshe mnozhestvo nereshennyh problem (hotya, est' i drugie mneniya, Virdzhiniya Trimbl v svoem doklade na tehasskom simpoziume skazala, chto na ee vzglyad v celom problema reshena - ostalos' utochnit' detali). Tem ne menee, sformirovalas' "standartnaya kartina", kotoraya, pravda, mozhet eshe ochen' sil'no izmenit'sya. Avtory opisyvayut detal'nye dvumernye raschety i dayut sootvetstvuyushii background. Sm. takzhe bolee korotkie obzory teh zhe avtorov: astro-ph/0212316 i astro-ph/0212317, i stat'yu "The Status of Core-collapse Supernova Simulations" astro-ph/0212438.
Authors: John N. Bahcall, M. C. Gonzalez-Garcia, C. Penya-Garay Commets: Background information at http://www.sns.ias.edu/~jnb
hep-ph/0212147
Solnechnye neitrino do i posle KamLAND
(Solar Neutrinos Before and After KamLAND)
Avtory pokazyvayut, chto novye dannye eksperimentov pozvolyayut kachestvenno uluchshit' verhnii predel na dolyu CNO cikla v svetimosti Solnca. Teper' etot predel sostavlyaet vsego 7 s nebol'shim procentov. Standartnaya model' predskazyvaet, chto dolya dolzhna byt' poryadka 1.5% ot Solnechnoi svetimosti, poetomu neobhodimy novye eksperimenty. Vtoraya stat'ya teh zhe avtorov, pomeshennaya v hep-ph razdele Arhiva, posvyashena, razumeetsya, blizkoi problematike. Avtory rassmatrivayut, chto dayut novye dannye, poluchennye na KamLAND, dlya solnechnyh neitrino. Pozhalui samym vazhnym yavlyaetsya utverzhdenie o tom, chto LMA (malen'kie ugly smeshivaniya) yavlyaetsya edinstvennym resheniem na urovne 4.7 sigma. Krome togo, nalagayutsya ochen' sil'nye ogranicheniya na dolyu steril'nyh neitrino sredi bornyh. Nu i konechno, avtory otmechayut, chto nestandartnye solnechnye modeli isklyuchayutsya na ochen' vysokom urovne dostovernosti. Takzhe sm. stat'yu V. Barger, D. Marfatia "KamLAND and solar neutrino data eliminate the LOW solution" hep-ph/0212126. I stat'yu "The Solar Neutrino Problem after the first results from Kamland" hep-ph/0212146.
Authors: Peter Erwin et al. Commets: LaTeX, 5 pages, 3 EPS figures. Uzhe nekotoroe vremya schitaetsya ustanovlennym, chto massy central'nyh chernyh dyr galaktik proporcional'ny massam ih baldzhei, a dlya ellipticheskih galaktik - ih polnym massam. No, okazyvaetsya, est' i bolee tonkie korrelyacii. Bolee massivnye chernye dyry soderzhatsya v bolee koncentrirovannyh k centru galaktikah i baldzhah. Otmechaetsya, takzhe, korrelyaciya massy chernoi dyry so svetimostyami galaktiki ili baldzha.
Authors: Charles Beichman Commets:Bioastronomy 2002, IAU Symposium 213, in press
astro-ph/0212337
Poisk planet zemnogo tipa: chto my dolzhny znat'?
(The Search for Terrestrial Planets: What Do we Need to Know?)
Dve stat'i odnogo avtora, napravlennye v materialy dvuh simpoziumov MAS. Terrestrial Planet Finder - kosmicheskii proekt NASA, polet kotorogo namechen na 2012 g. Prichem, poskol'ku dazhe Bush mladshii priznal poisk vnezemnoi zhizni prioritetnoi zadachei, to skoree vsego finansirovanie ne sorvetsya. V pervoi stat'e avtor v osnovnom obsuzhdaet perspektivy etoi missii. Vtoraya stat'ya posvyashena tomu, chto zhe my dolzhny znat', chtoby v polnoi mere ispol'zovat' vozmozhnosti, predostavlyaemye budushimi sputnikami. Nu i opyat' zhe obsuzhdaetsya Terrestrial Planet Finder. Konechno, stat'i vo mnogom peresekayutsya.
Authors: Mark A. Walker (Sydney Uni, Australia Telescope National Facility & Raman Research Institute), Geraint F. Lewis (Sydney Uni & Anglo-Australian Observatory) Commets: 28 pages, 12 figures, submitted to ApJ Nekotorye teorii ob'yasnyayut izmenenie svetimosti kvazarov na intervalah vremeni poryadka goda effektami mikrolinzirovaniya na telah planetnyh mass, raspredelennyh v mezhgalakticheskom prostranstve. No takie mikrolinzirovanie mozhet ob'yasnit' svoistva gamma-vspleskov. Maksimal'noe usilenie potoka dostigaetsya pri peresechenii sistemy kaustik, podobnyh pokazannym na risunke. Pri nalichii bol'shogo kolichestva linz struktura kaustik stanovitsya ochen' slozhnoi i ih peresechenie mozhet ob'yasnit' vse nablyudaemoe raznoobrazie vremennyh profilei gamma-vspleskov. Zametim, chto zdes' budut ochen' sil'ny parallakticheskie effekty i dazhe dostatochno blizkie nablyudateli budut videt' vspleski s profilyami raznoi formy. Po krainei mere kakaya-to chast' gamma-vspleskov mozhet ob'yasnyat'sya podobnym obrazom.
Authors: K.-H. Kampert et al. Commets: Proceedings to "XII International Symposium on Very High Energy Cosmic Ray Interactions", CERN, Geneva, Switzerland 15-20 July 2002, (5 pages, 4 figures) Kosmicheskie luchi sverhvysokih energii yavlyayutsya seichas odnoi iz samyh goryachih tem v astrofizike (naprimer, oni aktivno obsuzhdalis' na proshedshem Tehasskom simpoziume). Sredi posterov byl i ochen' interesnyi doklad ob eksperimente KASCADE. Stat'ya soderzhit kratkoe opisanie eksperimenta, osnovnoi zadachei kotorogo yavlyaetsya izmerenie t.n. "zheleznogo kolena" na energiyah ~ 10^17 eV (o himicheskom sostave kosmicheskih luchei i imeyushihsya v etoi oblasti problemah sm. svezhaishii obzor "The Chemical Composition of Cosmic Rays" astro-ph/0212348 togo zhe avtora).
Authors: K.-H. Kampert Commets: Invited paper presented at Vulcano Workshop 2002 "Frontier Objects in Astrophysics and Particle Physics", 20.-25. May, Vulcano (Italy) (8 pages, 2 figures) V etom korotkom obzore rassmotren himicheskii sostav kosmicheskih luchei v intervale energii ot 1015 do 1020 eV. Obsuzhdayutsya dannye eksperimentov BLANCA, DICE, Fly's Eye, HEGRA, HiRes i TUNKA. Pohozhe, chto pri priblizhenii k verhnei granice etogo diapazona dolya tyazhelyh yader v kosmicheskih luchah vozrastaet.
Authors: Patrick Slane Commets: 12 pages, Invited paper in Proceedings "The Universe viewed in Gamma-rays", eds. Enomoto, Mori, and Yanagita, Universal Academy Press, in press Na Tehasskom simpoziume dovol'no aktivno obsuzhdalis' nablyudeniya i teoriya pul'sarnyh tumannostei, osobenno dzhetov. V dannom obzore avtor rassmatrivaet dannye Chandry po ostatkam sverhnovyh i pul'sarnym tumannostyam. K sozhaleniyu, samye svezhie dannye po vneshnemu dzhetu u pul'sara v Parusah eshe ne uspeli popast' v obzor. No tem ne menee rezul'taty, privodimye v stat'e, ochen' interesny.
Authors: P. Barbeau, J.I. Collar, J. Miyamoto, I. Shipsey Commets: Presented at the 2002 IEEE Nuclear Science Symposium and Medical Imaging Conference, Norfolk VA, November 10-16. Submitted to IEEE Tran. Nucl. Sci. Five pages, eight figures "Registraciya rasseyaniya na yadrah nizkoenergichnyh (< neskol'kih desyatkov MeV) neitrino - svyatoi graal' sovremennoi neitrinnoi fiziki." Ochen' slozhnaya eksperimental'naya zadacha, nesmotrya na to, chto kogerentnoe rasseyanie na yadrah gorazdo bolee effektivno, chem vzaimodeistvie s otdel'nymi nuklonami. Razlichnye aspekty dannoi problemy podrobno rassmotreny. Avtory predlagayut ispol'zovat' Micropattern Gas Detectors, sdelannye iz nizkoradioaktivnyh materialov dlya registracii takih neitrino i proveli nekotorye eksperimental'nye testy. [Prim.: A ved' est' eshe reliktovye neitrino ...]
Authors: Ofer Lahav Commets: Invited review at the XVIIIth IAP meeting the Nature of Dark Energy'; Paris 2002; 10 pages (2 figures included) V poslednie gody vozros potok nablyudatel'nyh dannyh v kosmologii. Sredi prochego prisutstvuyut bol'shie obzory krasnyh smeshenii (Sloanovskii obzor, 2dF - dvuhgradusnyi obzor i dr.). V obzore Lahav rassmatrivaet vopros ob opredelenii parametrov temnoi energii po etim dannym. Suhoi ostatok takov: sami po sebe dannye obzorov ne dayut vozmozhnosti opredeleniya uravneniya sostoyaniya temnoi energii, no vmeste s drugimi dannymi (relikt i dr.) uzhe seichas dayut vazhnye verhnie predely, kotorye v budushem mogut byt' sushestvenno uluchsheny.
Authors: Oliver Zahn, Matias Zaldarriaga Commets: 13 pages, 19 figures Eta stat'ya v nekotorom smysle pereklikaetsya s predydushei (astro-ph/0212358). Rech' opyat' idet o proverke kosmologicheskih parametrov po dannym nablyudenii. Na etot raz avtory dumayut, kak opredelit' temp rasshireniya Vselennoi na moment rekombinacii po dannym sputnikov MAP (uzhe zapushen) i Planck. Voobshe zhe o sovremennom znanii kosmlogicheskih parametrov sm. nizhe stat'yu "The last stand before MAP: cosmological parameters from lensing, CMB and galaxy clustering" astro-ph/0212417.
Authors: Anatoly A. Svidzinsky Commets: 43 pages, 7 figures, to appear in Astrophysical Journal Kogda govoryat ob izluchenii neitronnyh zvezd, obychno rassmatrivayut elektromagnitnoe (teplovoe) izluchenie s poverhnosti i izluchenie neitrino iz centra neitronnyh zvezd. V dannoi stat'e rassmotren eshe odin mehanizm perenosa energii - besstolknovitel'nyi elektronnyi zvuk. Zvukovye vozmusheniya v elektronnoi komponente neitronnoi zvezdy rasprostranyayutsya po nei stol' zhe svobodno, kak i neitrino. Istochnikom takih zvukovyh vozbuzhdenii sluzhat vihrevye niti v sverhtekuchem vrashayushemsya yadre. Pri nalichii magnitnogo polya elektronnyi zvuk mozhet prevrashat'sya v magnitozvukovye volny, kotorye vblizi poverhnosti prevrashayutsya v elektromagnitnoe izluchenie.
Authors: Lawrence M. Krauss Commets: 4 pages, submitted to Ap. J. Lett Nesmotrya na bol'shie uspehi v nablyudatel'noi kosmologii v nashem znanii osnovnyh parametrov sushestvuet dovol'no bol'shaya neopredelennost' (hotya, udivitel'no, chto my voobshe tak horosho ih znaem!). V etoi korotkoi zametke (vsego 3 stranichki + risunok) avtor rassmatrivaet vozmozhnye ogranicheniya na vozrast Vselennoi (menee 20 milliardov let), a takzhe na parametr uravneniya sostoyaniya temnoi materii (w>-1.5, w=const).
Authors: V.S.Beskin Commets: full version, in "Accretion Disks, Jets, and High Energy Phenomena in Astrophysics", Proceedings of Session LXXVIII of Les Houches Summer School, Chamonix, France, August 2002, F.Menard, G. Pelletier, G.Henri, V. Beskin, and J. Dalibard eds. (EDP Science: Paris and Springer: Berlin), in preparation Uravnenie Greda-Shafranova (Grad-Shafranov) pozvolyayut reshat' ochen' mnogie stacionarye osesimmetrichnye zadachi. Odno iz polei ih prilozhenii - gidrodinamika, v tom chisle i v ramkah obshei teorii otnositel'nosti, t.e. vblizi kompaktnyh zvezd i chernyh dyr. Etomu i posvyashen dannyi kurs lekcii (eto deistvitel'no kurs - bolee 50 stranic). Vsem zhelayushim razobrat'sya posvyashaetsya.
Authors: S. Johansson, V. S. Letokhov Commets: Accepted for publication in Phys. Rev. Letters Rech' idet o lazernom izluchenii ot zvezdy Eta Kilya. Ob etom vy mozhete prochest' v stat'e "Eta Carinae - lazer, sozdannyi samoi prirodoi". Cikl sostoit ih 4 zven'ev - 4 urovnei i 4 perehodov mezhdu nimi v ionah odnokratno ionizirovannogo zheleza FeII (na risunke pokazany 2 blizkih cikla). Vozbuzhdenie cikla (perehod 1->4) proizvoditsya osnovnym izlucheniem zvezdy v linii L\alpha. Dlina volny L\alpha i perehoda 1->4 zametno ne sovpadayut. Odnako v opticheski plotnoi obolochke zvezdy L\alpha-fotony mnogokratno pereizluchayutsya i diffundiruyut po chastote iz-za effekta Dopplera. Perehody 4->3 i 2->1 - "obychnye" i proishodyat dostatochno bystro. A vot uroven' 3 (perehod 3->2) - metastabil'nyi. V sostoyanii 3 atomy sushestvuyut dostatochno dolgo v rezul'tate chego voznikaet inversnaya zaselennosti urovnei 2 i 3. Eto i est' "zvezdnyi lazer" - v obychnyh usloviyah liniya 3->2 ochen' slaba, no v radiativnom cikle chislo fotonov v etoi linii takoe zhe, kak i v ostal'nyh perehodah cikla.
Authors: Volker Bromm, Abraham Loeb Commets: Submitted to ApJ, 10 pages, 9 figures, version with full resolution Figs at http://cfa-www.harvard.edu/~vbromm/HIGH/apj.ps S pomosh'yu SPH modelirovaniya avtory rassmatrivayut process obrazovaniya pervyh (v nekotorom smysle "zachatochnyh") sverhmassivnyh chernyh dyr v central'nyh oblastyah galaktik. Metallichnost' polagaetsya nulevoi (tochnee, himsostav opredelyaetsya pervichnym nukleosintezom). Po vsei vidimosti eto vunuzhdennoe predpolozhenie. Avtory rassmatrivayut krasnye smesheniya poryadka 10, a pervye zvezdy obrazovalis' na z=20-30 i uzhe uspeli vzorvat'sya. Odnako, v stat'e privodyatsya argumenty v pol'zu primenimosti dannogo predpolozheniya. V raschetah (v zavisimosti ot parametrov galaktiki) poluchayutsya kak odinochnye, tak i dvoinye chernye dyry. Pervye privodyat k poyavleniyu kvazarnoi aktivnosti eshe do epohi vtorichnoi ionizacii.
Authors: Xiaomin Wang et al. Commets: Combined CMB data, window and covariance matrix for January "MAP vs World" contest at http://www.hep.upenn.edu/~max/cmblsslens.html or from xiaomin@hep.upenn.edu Sputnik MAP uzhe letaet i sobiraet dannye. V sleduyushem godu poyavyatsya pervye rezul'taty, a potomu narod podvodit itogi. V obzore daetsya svodka opredelenii osnovnyh kosmologicheskih parametrov po dannym razlichnyh nablyudenii, a takzhe perechislyayutsya osnovnye problemy, sushestvuyushie v nablyudatel'noi kosmologii (kak-to "problema sigma-8").
Authors: Piercarlo Bonifacio (1) and Elisabetta Caffau (2) ((1) INAF-Osservatorio Astronomico di Trieste, (2)Liceo Scientifico Leonardo da Vinci, Paris, France) Commets: A&A accepted Neskol'ko poslednih let astronomy nahodyatsya v neobychnoi, vpervye sozdavsheisya situacii - sovremennye nazemnye i kosmicheskie observatorii vydayut ogromnyi potok informacii, kotoryi obychnymi metodami ne uspevayut analizirovat'. Izuchayutsya samye zlobodnevnye problemy, a vse ostal'noe osedaet v arhivah - na budushee. Edinstvennyi razumnyi vyhod - avtomaticheskaya obrabotka nablyudenii. Nekotoroe vremya nazad byli stat'i pro avtomaticheskuyu klassifikaciyu krivyh bleska peremennyh zvezd. Teper' - analiz spektrov. Nu a detali algoritma, tochnost' i t.d. - v stat'e.
Authors: K.D.Kokkotas et al. Commets: 4 pages, 2 figures Rech' idet o neitronnyh (kvarkovyh i t.p) zvezdah, chei radius ne prevoshodit tri shvarcshil'dovskih. V etom sluchae vokrug zvezdy obrazuetsya (kak vokrug chernoi dyry) ergosfera. Takaya situaciya mozhet soprovozhdat'sya vozniknoveniem ves'ma specificheskoi neustoichivosti (w-mode instability). Eto sobstvenno neustoichivost' prostranstva-vremeni. Avtory rassmatrivayut vozmozhnost' voniknoveniya neustoichivosti v real'noi astrofizicheskoi situacii, a takzhe obsuzhdayut astrofizicheskie proyavleniya.
Authors: Christian Y. Cardall (Oak Ridge National Laboratory and University of Tennessee, Knoxville) Commets: Contribution to the proceedings of the 4th International Workshop on the Identification of Dark Matter (IDM2002), held in York, England 2-6 September 2002, to be published by World Scientific. 10 pages, 1 figure Izuchaya razlichnymi sposobami vzryvy sverhnovyh mozhno poluchat' ochen' raznoobraznuyu informaciyu - ot zakona rasshireniya Vselennoi i svoistv temnoi materii do uravneniya sostoyaniya neitronnogo veshestva i sushestvovaniya ekzoticheskih chastic. No dlya etogo nado horosho ponimat' kakie processy v nih proishodyat. I edinstvennyi put' zdes' - detal'noe chislennoe modelirovanie. No do segodnyashnego dnya pri modelirovanii kollapsa i vzryva sverhnovoi uchityvalis' ne vse fizicheskie processy - prosto potomu, chto dlya takih raschetov ne hvatilo by moshnosti komp'yuterov. TeraScale Supernova Initiative - proekt v kotorom v blizhaishie neskol'ko let predpolagaetsya preodolet' eti ogranicheniya.
Authors: E. Buchlin, V. Aletti, S. Galtier, M. Velli, G. Einaudi, J.-C. Vial Commets: 10 pages, 9 figures Accepted for publication in Astronomy & Astrophysics Ideya etoi stat'i, po-moemu, sil'no pereklikaetsya s temi, chto vyskazal Stiven Vol'fram (razrabotchik sistemy analiticheskii vychislenii Matematika) v svoei knige knige "A new kind of science", vyshedshei 14 maya 2002 goda (sm. zdes'). A v stat'e predlozheno smodelirovat' rasprostranenie vozmushenii vdol' magnitnyh petel' v Solnechnoi magnitosfere s pomosh'yu 3-mernogo kletochnogo avtomata. Podhod i rezul'taty ochen' interesnye.
Arhiv statei, voshedshih v predydushie vypuski.
Razdely arhiva (s iyulya 2002 g.): Poleznye astronomicheskie ssylki. Obzornye stat'i v astro-ph s 2001 g. |
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