Novosti nauki |
The R.A.P. Project |
17.12.02. astro-ph za 09 - 13 dekabrya 2002 goda: izbrannye stat'i |
Teper' my budem starat'sya vydelit' "luchshih iz luchshih".
Authors: P. Laird, R. Bergamasco, V. Berube et al Authors: Daniel E. Holz and Scott A. Hughes Authors: Alain Riazuelo, Jean-Philippe Uzan, Roland Lehoucq, Jeffrey Weeks Author: Joseph Katz (The Racah Institute of Physics, Jerusalem, Israel.) Authors: Gia Dvali, Andrei Gruzinov, and Matias Zaldarriaga Sushestvuyut kosmologicheskie teorii v kotoryh nizkii temp uskoreniya Vselennoi ob'yasnyaetsya izmeneniem zakona tyagoteniya na ochen' bol'shih rasstoyaniyah (poryadka gorizonta ili na eshe bOl'shih). Odnako takie izmeneniya mogut byt' obnaruzheny i na malyh rasstoyaniyah, naprimer s pomosh'yu precizionnyh izmerenii rasstoyaniya v sisteme Zemlya-Luna.
Authors: EROS Collaboration Commets: 6 pages, 3 figures Pyat' let proekt EROS kazhduyu noch' nablyudaet za Malym Magellanovym Oblakom v poiskah sobytii gravitacionnogo mikrolinzirovaniya. V hode etogo eksperimenta byli zafiksirovany chetyre ochen' dlinnyh sobytiya, kotorye, vozmozhno, proizvedeny linzami ne prinadlezhashimi galo Galaktiki. Iz etih dannyh mozhno poluchit' ogranichenie, chto ne bolee 25% massy galo mozhet soderzhat'sya v ob'ektah sostoyashih iz temnoi materii s massami ot 2.10-7 Mo do 1 Mo.
Authors: S. I. Ipatov and J. C. Mather Commets: "Advances in Space Research" (Proc. of COSPAR-2002 (10-19 October 2002, Houston, TX, USA), COSPAR02-A-00845), submitted Byla rasschitana evolyuciya orbit neskol'kih tysyach komet prohodyashih blizko ot Yupitera (podobnyh kometam semeistva Yupitera) na intervale v 10 mln. let. Bylo naideno, chto tol'ko malaya dolya komet popadaet v semeistvo Apollo (s bol'shoi poluos'yu < 2AE), v semeistvo Aten ili v semeistvo komet dvizhushihsya vnutri orbity Zemli (afelii < 0.983AE). Vyvod - bol'shaya chast' proletayushih blizko ot Zemli ob'ektov ne iz kometnogo semeistva Yupitera, veroyatno eto byvshie Transneptunovskie ob'ekty.
Authors: P. Laird, R. Bergamasco, V. Berube et al Commets: 9 pages. To appear in SPIE meeting in Hawaii August 2002. Astronomical Telescopes and Instrumentation Teleskopy stanovyatsya vse bol'she, vse bol'she stanovitsya potrebnost' v adaptivnoi optike. Avtory ispytali zhidkoe zerkalo, sostoyashee iz ferromagnitnoi zhidkosti (kolloida) na osnove vody i masla, upravlyaemoi magnitnym polem, pokrytoi tonkim sloem otrazhayushego soderzhashego serebro metallokolloida. Polucheny interesnye eksperimental'nye rezul'taty.
Authors: T. Jacobson, S. Liberati, and D. Mattingly Commets: 13 pages, 3 figures Narushenie lorencevskoi invariantnosti prostranstva-vremeni mozhet proishodit' na energiyah blizkih k Plankovskim i proyavlyat'sya v poyavlenii u fotonov v vakuume dispersii (t.k. ih skorost' budet otlichat'sya ot c). Nablyudeniya sinhrotronnogo izlucheniya Krabovidnoi tumannosti pozvolilo poluchit' novoe ogranichenie na harakternoe znacheniya etoi energii (pri kotoroi dispersiya stanovitsya sushestvennoi) E>4.5.1027 GeV. Eta velichina na 4 poryadka vyshe Plankovskoi energii i na 5 poryadkov vyshe predydushih ogranichenii.
Authors: Shou-Guan Wang, Zong-Hong Zhu, Zhen-Long Zou, Yuan-Zhong Zhang Commets: 5 pages, no figure, Latex file Journal-ref: Int.J.Mod.Phys. D11 (2002) 1061-1065 Davno izvestna ideya ispol'zovat' pul'sary dlya registracii sverhnizkochastotnyh gravitacionnyh voln s periodami ot 1 do 100 let. Teper' dlya etoi zadachi predlagaetsya postroit' special'nyi 50 m radioteleskop, kotoryi budet regulyarno izmeryat' taiming 10 naibolee stabil'nyh millisekundnyh pul'sarov.
Authors: Daniel E. Holz and Scott A. Hughes (KITP, UCSB) Commets: 4 pages, 4 figures Okazyvaetsya slivayushiesya dvoinye chernye dyry mozhno ispol'zovat' kak standartnye svechi - istochniki gravitacionnyh voln s tochno izvestnoi svetimost'yu. Nablyudaya za izmeneniem amplitudy i chastoty signala my mozhem opredelit' vse parametry etoi sistemy i vychislit' krasnoe smeshenie i rasstoyanie do nee s tochnost'yu 1%! (Tol'ko, po-moemu, etot fakt byl dostatochno davno izvesten.)
Authors: Alain Riazuelo, Jean-Philippe Uzan, Roland Lehoucq, Jeffrey Weeks Commets: 32 pages, 49 figures, submitted to PRD. Higher resolution figures available on demand Vselennaya mozhet imet' slozhnuyu topologiyu (tory, skleiki i t.p.) Budet li eto skazyvat'sya na raspredelenii neodnorodnostei temperatury reliktovogo izlucheniya? Esli da - to kak? Stat'ya posvyashena osobennostyam chislennogo modelirovaniya, no v nei mnogo model'nyh kartinok.
Authors: G. Boudoul & A. Barrau Commets: Proceedings of the International Conference on Theoretical Physics (TH2002), to appear in Annales Henri Poincare Malen'kie chernye dyry obrazuyutsya na rannih etapah evolyucii Vselennoi, esli perepady plotnosti togda byli dostatochno veliki. V etoi stat'e priveden obzor poslednih dostizhenii v etoi oblasti. Rassmotreny voprosy poiska takih chernyh dyr (cherez kosmicheskie i gamma-luchi), ispol'zovaniya pervichnyh chernyh dyr dlya izucheniya Vselennoi na ochen' malyh kosmologicheskih shkalah (v ochen' rannem vozraste). V konce rassmotreny nekotorye effekty "novoi fiziki" - vliyanie vysshih izmerenii na obrazovanie pervichnyh chernyh dyr.
Authors: G.J. Gounaris and G. Moultaka Commets: 6 pages, no figures. e-mail: gounaris@physics.auth.gr Report-no: THES-TP 2002/03, PM/02-55 Eksperimenty poslednih let ustanovili, chto razlichnye sorta neitrino smeshivayutsya (perehodyat drug v druga) i dostatochno sil'no ogranichili vozmozhnye znacheniya parametrov smeshivaniya. A kak budut raspredeleny po aromatam (sortam) neitrino prihodyashie iz kosmosa? V dannoi rabote daetsya prostoi analiticheskii otvet na etot vopros.
Authors: Francois Schweizer (Carnegie Observatories, Pasadena) Commets: 11 pages, LaTeX, 6 figures (= 10 EPS files); uses newpasp.sty. To appear in "New Horizons in Globular Cluster Astronomy," eds. G. Piotto, G. Meylan, G. Djorgovski, & M. Riello (ASP, San Francisco), 2003 Sliyanie bogatyh gazom galaktik privodit k nachalu massovogo obrazovaniya zvezd i skoplenii. Za vremya sliyaniya rozhdayutsya tysyachi skoplenii, no tol'ko samye massivnye i kompaktnye iz nih perezhivayut pervyi milliard let i prevrashayutsya v obychnye sharovye skopleniya. A v techenie pervogo milliarda let s nachala sliyaniya eti sharovye skopleniya "vtorogo pokoleniya" vyglyadyat kak molodye skopleniya galo s posti solnechnym himicheskim sostavom. Podobnye sharovye skopleniya s promezhutochnymi vozrastami (2-5 mlrd. let) nedavno byli naideny v primerno 10 ellipticheskih galaktikah.
Authors: G. Gavazzi et al. Commets: 5 pages, 2 figures, accepted for pubblication in Astronomy & Astrophysics Novyi sait "GOLDMine" (Galaxy On Line Database Milano Network) http://goldmine.mib.infn.it soderzhit dannye o nablyudeniyah 3267 galaktik skoplenii Virgo i Coma na raznyh dlinah voln v opticheskom diapazone. Tam zhe soderzhatsya izobrazheniya galaktik.
Authors: Milos Milosavljevic, David Merritt Commets: 8 pages, invited contribution to the Proceedings of the 4th LISA Symposium, State College, PA, July 2002 Esli dve galaktiki s chernymi dyrami v centrah slivayutsya, to cherez nekotoroe vremya obe chernyh dyry okazyvayutsya v centre (minimume gravitacionnogo potenciala) obrazovavsheisya galaktiki, gde obrazuyut dvoinuyu sistemu. Gravitacionnyi volny ot takoi dvoinoi mogut byt' zaregistrirovany kosmicheskim detektorom LISA. Dannaya stat'ya posvyashena processam, kotorye budut proishodit' v takoi sisteme, kogda rasstoyanie mezhdu chernymi dyrami stanet men'she parseka.
Authors: Richard de Grijs, Nate Bastian, Henny J.G.L.M. Lamers Commets: accepted for publication in the ApJ Letters; 10 pages in AASTEX preprint format; including 2 postscript figures Samaya populyarnaya segodnya model' dinamicheskoi evolyucii zvezdnyh skoplenii predskazyvaet, chto stepennaya funkciya svetimosti molodyh skoplenii dolzhna bystro prevrashat'sya v gaussovu funkciyu svetimostei "staryh" sharovyh skoplenii, podobnyh tem, chto nablyudayutsya v nashei Galaktike. Pohozhe, chto nablyudayushayasya centre v galaktiki M82 sistema sharovyh skoplenii s vozrastami okolo 1 Glet nahoditsya kak raz na stadii perehoda mezhdu etimi dvumya sostoyaniyami.
Author: Rainer Beck Commets: 10 pages with 3 figures. Mezhzvezdnye magnitnye polya dostatochno sil'ny: do 25.10-6 G v spiral'nyh vetvyah i do 40.10-6 G vblizi yader galaktik. V spiral'noi galaktike NGC 6946 srednyaya plotnost' energii magnitnyh polei vyshe, chem teplovoi energii gaza. Magnitnye polya kontroliruyut evolyuciyu plotnyh oblakov i, vozmozhno, global'nuyu effektivnost' zvezdoobrazovaniya. Potoki gaza i udarnye volny v spiral'nyh vetvyah i barah modificiruyutsya magnitnymi polyami. I tak dalee ...
Authors: Pau Amaro-Seoane Commets: 9 pages, no figures, to appear in 2003, Carnegie Observatories Astrophysics Series, Vol. 1: Coevolution of Black Holes and Galaxies, ed. L. C. Ho (Pasadena: Carnegie Observatories, http://www.ociw.edu/ociw/symposia/series/symposium1/proceedings.html). Needs caps.cls and cupbook.cls (included) Vozmozhnost' sushestvovaniya v centre kvazara sverhmassivnoi zvezdy s massoi 107-109 Mo i svetimost'yu 1012 Lo ("magnetoid") rassmatrivalas' i byla ochen' populyarnoi v 60-e - 70-e gody. Svetimost' kvazarov v etoi modeli ob'yasnyalas' akkreciei na takoi sverhmassivnyi ob'ekt (Lynden-Bell 1969, u nas etoi tematikoi zanimalsya L.Ozernoi). Eta, dostatochno ekzotichnaya ideya, segodnya ispytyvaet vtoroe rozhdenie v svyazi s otkrytiem sverh massivnyh chernyh dyr v centrah mnogih galaktik. Koncepciya sverhmassivnoi (>5.104 Mo) zvezdy, pogruzhennoi v plotnoe zvezdnoe skoplenie mozhet ob'yasnit' ryad nablyudaemyh v kvazarah yavlenii. V dannoi stat'e chislenno izuchena dinamika vzaimodeistviya sverhmassivnoi zvezdy m okruzhayushim ee plotnym zvezdnym polem.
Author: Joseph Katz (The Racah Institute of Physics, Jerusalem, Israel.) Commets: 35 pages,6 figures "Nulevym" zakonom termodinamiki yavlyaetsya utverzhdenie, chto termodinamicheskii podhod mozhet primenyat'sya tol'ko k sistemam u kotoryh est' sostoyanie ravnovesiya. A u samogravitiruyushih (gravitacionno-svyazannyh) sistem ego net - v gravitacionnuyu potencial'nuyu yamu (kak i v dolgovuyu) mozhno padat' beskonechno dolgo. Odnako nablyudayushiesya galaktiki i sharovye skopleniya vyglyadyat dostatochno ravnovesnymi. Poetomu postoyanno delayutsya popytki tak modificirovat' klassicheskuyu termodinamiku, chtoby ona mogla primenyat'sya i k zvezdnym skopleniyam. Etomu i posvyashen dannyi obzor ili, skoree, uchebnyi kurs.
Authors: M. De Pasquale, L. Piro, R. Perna et al. Commets: 19 pages, 5 figures. To be published in The Astrophysical Journal Po dannym BeppoSAX (do fevralya 2001) 90% gamma-vspleskov obladayut rentgenovskimi poslesvecheniyami, a opticheskie poslesvecheniya est' tol'ko primerno u poloviny vspleskov. Razlichayutsya li rentgenovskie poslesvecheniya u "opticheski yarkih" vspleskov (obladayushih opticheskim poslesvecheniem) i u "temnyh"? Otvet - DA. So statisticheskoi znachimost'yu 99.8% pokazano, chto "temnyh" gamma-vspleskov rentgenovskii potok v diapazone 1.6-10 keV v srednem v 5 raz vyshe, chem u "yarkih". Est' i nekotorye drugie otlichiya.
Arhiv statei, voshedshih v predydushie vypuski.
Razdely arhiva (s iyulya 2002 g.): Poleznye astronomicheskie ssylki. Obzornye stat'i v astro-ph s 2001 g. |
|
Publikacii s klyuchevymi slovami:
elektronnye preprinty - obzory - astro-ph
Publikacii so slovami: elektronnye preprinty - obzory - astro-ph | |
Sm. takzhe:
Vse publikacii na tu zhe temu >> |