The R.A.P. Project (Reviews of Astro-Ph)
Nasha Galaktika
Authors: Gerard Gilmore et al.
Comments: APJL 574 L39 (July 20, 2002)
"Pogoda byla prekrasnaya, princessa byla uzhasnaya...."
Nasha Galaktika - tozhe kannibal.
Ona poedaet bolee melkih sosedei.
Avtory stat'i obnaruzhili ostatki takogo epizoda.
V rezul'tate spektroskopicheskogo izucheniya 2000 zvezd klassov F i G
na rasstoyaniyah 0.5-5 kpk ot galakticheskoi ploskosti polucheno ukazanie
na epizod "poglosheniya" nashei Galaktikoi sosedki 10-12 milliardov let nazad.
Authors: A. Ibukiyama et al.
Comments: 45 pages, 21 figures, and 5 tables. Accepted to Astronomy & Astrophysics
V rabote poluchena zavisimost' vozrast-metallichnost' dlya 1658 zvezd,
dlya kotoryh sushestvuyut tochnye izmereniya rasstoyanii po dannym sputnika
HIPPARCOS. Sredi zvezd est' ob'ekty tonkogo i tolstogo diskov, a takzhe
neskol'ko zvezd galo. Obsuzhdayutsya razlichiya dlya raznyh sostavlyayushih
Galaktiki.
Authors: Rene A. Mendez
Comments: 11 pages, 5 figures. Uses aa.cls style file. Accepted for publication by A&A
Avtor nahodit podtverzhdeniya tomu, chto znachitel'naya chast' temnoi materii v Solnechnoi okrestnosti mozhet ob'yasnyat'sya starymi belymi karlikami.
Authors: A. Goldwurm et al.
Comments: 16 pages, 5 figures, submitted to ApJ Letters
Kak horosho izvestno blizhaishaya sverhmassivnaya chernaya dyra nahoditsya v centre nashei Galaktiki (massa dyry okolo 2 000 000 mass Solnca). Odnako, tak zhe horosho izvestno, chto etot monstr "spit": nikakoi burnoi aktivnosti ili yarkogo istochnika ne nablyudaetsya (eto pytayutsya ob'yasnyat', naprimer, t.n. advekcionno-diminirovannym rezhimom akkrecii, sm. nizhe). Lish' vremya ot vremeni proishodyat nebol'shie vspyshki v rentgenovskom diapazone.
Authors: Gilberto C. Gomez, Donald P. Cox
Comments: 33 pages, 17 figures. Accepted for publication in Apj. Better quality images in http://www.journals.uchicago.edu/ApJ/journal/preprints/ApJ55782.preprint.pdf
Na samom dele rech' tut poidet srazu o chetyreh stat'yah (pocheum-to chasto stat'i po blizkim temam nezavisimo poyavlyayutsya v odnom vypuske astro-ph).
Gomez i Cox v svoei rabote predstavlyayut rezul'taty trehmernogo modelirovaniya gazovoi struktury Galaktiki. Vazhen uchet spiral'noi struktury (v svyazi s etim avtory predstavlyayut vtoruyu stat'yu astro-ph/0207635, posvyashennuyu analiticheskoi approsimacii gravitacionnogo potenciala rukava Galaktiki).
Krome etih rabot poyavilas' stat'ya po turbulentnosti v galakticheskih diskah (Wada et al. astro-ph/0207641). Zdes' avtory provodyat dvumernye raschety s uchetom samogravitacii veshestva mezhzvezdnoi sredy.
Nu i nakonec rabota Mir Abbas Jalali i Mehdi Abolghasemi (astro-ph/0207644) posvyashena analiticheskim issledovaniyam gazovyh diskov.
Rezul'taty, poluchennye v pervyh dvuh rabotah, primenyayutsya v osnovnom k nashei Galaktike, v tret'ei - k NGC 2915, a v poslednei - k Bol'shomu Magellanovu Oblaku.
Authors: Nikos Prantzos
Comments: Invited review talk in The Gamma-Ray Universe (XXII Moriond Astrophysics meeting), 14 pages, 5 figs. Proceedings edited by A. Goldwurm et al. (in press)
V stat'e dan obzor "zvezdnoi radioaktivnosti". Rech' idet o sinteze radioaktivnyh elementov massivnymi zvezdami (v tom chisle i pri vzryvah sverhnovyh). Dan interesnyi istoricheskii obzor.
Authors: N. Prantzos
Comments: 12 pages, 8 figures. Invited talk in "Galaxy Evolution III: From Simple Approaches to Self-Consistent Models" (Kiel, Germany, July 16-20, 2002) Eds. G. Hensler et al., in press
Rassmatrivaetsya postroenie modelei evolyucii diskovyh galaktik, v pervuyu ochered' - nashego Mlechnogo Puti. Predstavleny rezul'taty modelirovaniya: sinteticheskie spektry, razlichnye korrelyacii mezhdu parametrami i t.d.
Authors: R. Schodel, T. Ott, R. Genzel, R. Hofmann, M. Lehnert, A. Eckart, N. Mouawad, T. Alexander, M.J. Reid, R. Lenzen, M. Hartung, F. Lacombe, D. Rouan, E. Gendron, G. Rousset, A.-M. Lagrange, W. Brandner, N. Ageorges, C. Lidman, A.F.M. Moorwood, J. Spyromilio, N. Hubin, K.M. Menten
Commets: 13 pages, 3 figures, scheduled for publication in Nature on 17 Oct 2002
Eto ta novost', iz-za kotoroi poslednyuyu nedelyu shumelo televidenie i gazety. 17 oktyabrya dannaya stat'ya byla opublikovana v Nature.
Nablyudeniya dvizheniya zvezd, naibolee blizkih k centru nashei Galaktiki - ob'ektu Sgr A*, dali samye zhestkie ogranicheniya na massu central'nogo ob'ekta i ego strukturu. Nablyudeniya velis' v blizhnem infrakrasnom diapazone na odnom iz 8-m teleskopov VLT. Bylo obnaruzheno, chto odna iz zvezd dvizhetsya po orbite s poluos'yu a=5.5 svetovyh dnei i periodom obrasheniya 15.2 goda. Pri etom pericentr orbity raspolozhen vsego v 17 svetovyh chasah ot centra Galaktiki (124 astronomicheskih edinicy, chto primerno v 3 raza bol'she udaleniya Plutona ot Solnca). Ocenka massy chernoi dyry + toi chasti central'nogo skopleniya, kotoraya popadaet vnutr' orbity etoi zvezdy, sostavlyaet 3.7+/-1.5x106Mo. Naibolee veroyatnaya model' raspredeleniya plotnosti vyglyadit tak: v centre - chernaya dyra massoi 2.6+/-0.2x106Mo, okruzhennaya skopleniem zvezd radiusom 0.34 pk s plotnost'yu 3.9x106Mo/pk3, za predelami etogo yadra plotnost' zvezd padaet stepennym obrazom (s pokazatelem -1.8).
Authors: Tsuyoshi Sakamoto (The Graduate University for Advanced Studies), Masashi Chiba (NAOJ) and Timothy C. Beers (Michigan State University)
Commets: 14 pages, including 9 figures and 3 tables, accepted for publication in Astronomy and Astrophysics
Uchteny novye dannye pro karlikovye galaktiki - sputniki Mlechnogo Puti, osobenno pro vysokoskorostnye ob'ekty. Itogo: massa nashei Galaktiki - 2.2.1012Mo.
Authors: K. Ebisawa et al.
Commets: 7 pages, Presented at "X-ray surveys in the light of new observations", 4-6 September, Santander, Spain. 4 pages with 4 figures
Avtory predstavlyayut svoi nablyudeniya Galaktiki (ploskosti, centra) na sputnikah Chandra i ASCA. V stat'e korotko, no ponyatno rasskazyvaetsya pro galakticheskie istochniki raznyh tipov.
Sm. takzhe korotkie zametki teh zhe avtorov: astro-ph/0210682, astro-ph/0210683.
Authors: Gerry Gilmore
Commets: review for Cozumel conference, Galaxy Evolution: Theory and Observations eds V Avila-Reese, C Firmani, C Frenk & C Allen Rev Mex AA 10pp, 8.ps and 4 .jpg figures
"Zvezdnye populyacii - okamenevshaya zapis' evolyucii Galaktiki". Stat'ya predstavlyaet soboi dovol'no prostoi i neglubokii obzor voprosov formirovaniya nashei Galaktiki i Mestnoi gruppy. Naibol'shee vnimanie avtory udelyayut samym starym podsistemam Mlechnogo puti - baldzhu, tolstomu disku i galo. Izuchenie etih processov pozvolit pravil'no ponyat' to, chto my vidim v galaktikah na bol'shih z.
Authors: J.L.Han, R.N.Manchester, G.J.Qiao and A.G.Lyne
Commets: 4 pages, with good illustrations of B-field structure. To appear in "Radio Pulsars", APS Conf. Ser., editted by M. Bailes, D. Nice, & S. Thorsett
Pul'sary ispuskayut sil'no polyarizovannoe radioizluchenie. Prohodya cherez mezhzvezdnuyu plazmu s magnitnym polem ploskost' polyarizacii takogo izlucheniya povorachivaetsya. I eto odin iz samyh moshnyh na segodnyashnii den' instrumentov, pozvolyayushih nam issledovat' magnitnoe pole nashei Galaktiki. Kak vyglyadit struktura magnitnogo polya Galaktiki v ee ploskosti vblizi ot Solnca pokazano na risunke, kotoryi vzyat iz etoi stat'i. Tochki, kruzhki i kvadraty - pul'sary po kotorym stroilas' eta kartina.
Authors: Masaaki Sakano et al.
Commets: 4 pages, 2 figures, uses shuzenji.sty; Proc. of 'Japan-Germany Workshop on Galaxies and Clusters of Galaxies', 29-31 Oct. 2002, Shuzenji, Japan; Manuscript with full size figures are found in http://www.star.le.ac.uk/~mas/research/paper/#Sakano2002jg
Fakticheski dlya vseh rentgenovskih sputnikov odnoi iz osnovnyh mishenei yavlyaetsya Galakticheskii centr. Rech' idet ne tol'ko (i ne stol'ko) o sverhmassivnoi chernoi dyre - v nashei Galaktike ona kak raz malo izluchaet. Delo v tom, chto oblast' centra Galaktiki (neskol'ko gradusov) plotno naselena istochnikami raznyh tipov. Vspomnim naprimer dlitel'nye nablyudeniya na Kvante, na Granate, kotorye dali mnogo novyh interesnyh rezul'tatov. V etoi korotkoi zametke avtory summiruyut osnovnye rezul'taty po centru Galaktiki, poluchennye k nastoyashemu momentu na sputnike XMM-Newton. Prichem zdes' kak raz rasskazyvaetsya o Sgr A* (chernoi dyre) i blizlezhashih strukturah.
Authors: C. Motch, O. Herent, P. Guillout
Commets: Proceedings of the "X-ray surveys, in the light of the new observatories" workshop, Astronomische Nachrichten, in the press (4 pages, 3 figures, uses an.cls)
Apparatura sputnika XMM-Newton ochen' chuvstvitel'na, chto pozvolyaet videt' slabye istochniki. Eto oznachaet, kak nablyudeniya dalekih vnegalakticheskih ob'ektov, tak i issledovaniya blizkih slabyh istochnikov - zvezd, akkreciruyushih dvoinyh v "vyklyuchennom" sostoyanii i t.d. Dlya issledovanii vnegalakticheskih istochnikov obychno vybirayut napravleniya vdali ot ploskosti Galaktiki. Svyazano eto s "perenaselennost'yu" izobrazhenii, sdelannyh v +/- 20 gradusah ot galakticheskogo ekvatora (krome togo, mozhet byt' vazhno pogloshenie). Razobrat'sya v meshanine mnozhestva slabyh istochnikov ochen' trudno, no mozhno. Imenno ob etom rasskazyvayut avtory v svoei korotkoi zametke. Oni opisyvayut popytku opticheskogo otozhdestvleniya galakticheskih istochnikov XMM-Newton. V osnovnom obnaruzheny aktivnye zvezdy, no est' i drugie ob'ekty.
Authors: Aya Bamba et al.
Commets: 17 pages, 9 figures; to appear in ApJ
V obzore byli naideny 3 zhestkih diffuznyh istochnika: G11.0+0.0, G25.5+0.0 i G26.6-0.1. Spektr i linii izlucheniya etih ob'ektov mogut byt' ob'yasneny kak opticheski tonkoi goryachei termicheski ravnovesnoi plazmoi, tak i ee neravnovesnoi ionizaciei. Rasstochnie do istochnikov 1-8 kpk (vychis po kolichestvu vodoroda na luche zreniya v predpolozhenii srednei plotnosti v diske galaktiki 1 H/sm3). Razmery istochnikov 4.5-27 pk, svetimosti - (0.8-23)x1033 erg/s. Eto ochen' pohozhe na ostatki sverhnovyh molodogo ili umerennogo vozrasta, pri etom oni mogut byt' kak obolochechnymi ostatkami, tak i plerionami (t.e. soderzhat' vnutri sebya molodoi pul'sar).
Authors: Carla Cacciari, Gisella Clementini
Commets: 19 pages, 2 Postscript figures, Latex, uses svmult.cls. To be published in tellar Candles'', Lecture Notes in Physics ( http://link.springer.de/series/lnpp)
Podrobno opisyvaetsya metodika opredeleniya rasstoyanii do sharovyh zvezdnyh skoplenii po nablyudeniyam zvezd tipa RR Liry. Hotya sama metodika sushestvkt davno, odnako uchenye stremyatsya uluchshit' tochnost', i zdes' "mnogoe sdelano, no mnogoe eshe predstoit".
Sm. takzhe stat'yu "Blue Supergiants as a Tool for Extragalactic Distances - Theoretical Concepts" astro-ph/0301621, posvyashennuyu opredeleniyu rasstoyanii po nablyudeniyam golubyh sverhgigantov.
Authors: Sergei Nayakshin, Rashid Sunyaev
Commets: 5 pages, 5 figures, submitted to MNRAS
Vokrug nashei central'noi chernoi dyry mozhet sushestvovat' neaktivnyi holodnyi
akkrecionnyi disk, ostavshiisya (iz-za nizkoi vyazkosti) ot "burnoi molodosti"
Sgr A*, kogda temp akkrecii byl vysok. Teper' etot disk "zasasyvaet"
goryachii gaz, ne davaya emu padat' v chernuyu dyru: gaz osedaet v diske na
otnositel'no bol'shih rasstoyaniyah ot chernoi dyry. Vse eto horosho ob'yasnyaet
nizkuyu svetimost' (prezhde vsego v radio) nashei "glavnoi chernoi dyry".
Zametit' sam disk ochen' neprosto, t.k. on dolzhen byt' ochen' tonkih (tipichnoe
otnoshenie radiusa k tolshine poryadka 1000). Odnako, disk mozhet proyavit' sebya
iz-za prisutstviya zvezd (v centre Galaktiki ih mnogo). Zvezdy mogut
zatmevat'sya diskom (esli hvataet opticheskoi tolshi). Krome togo
solncepodobnye zvezdy mogut vyzyvat' rentgenovskie i IK vspyshki, prohodya
cherez disk. V stat'e detal'no rassmatrivayut kak raz eti vozmozhnye proyavleniya
holodnogo akkrecionnogo diska v centre nashei Galaktiki.
Authors: A. M. Ghez et al.
Commets: 14 pages, Latex, Accepted for Publication in ApJ Letters
Vpervye udalos' zaregistrirovat' spektral'nye (absorbcionnye) linii ot zvezdy, vrashayusheisya ochen' blizko ot "nashei" sverhmassivnoi chernoi dyry. Zvezda okazalas' massivnoi (M poryadka 15 mass Solnca). Dovol'no molodoi: ona eshe nahoditsya na glavnoi posledovatel'nosti. Eto paradoksal'nyi rezul'tat, t.k. schitalos', chto tak blizko ot chernoi dyry, gde prilivnye sily ochen' veliki, zvezdy ne obrazuyutsya. krome togo, vremya migracii zvezdy na takuyu orbity (esli ona rodilas' tam, gde prilivy slabee) bol'she vremeni zhizni stol' massivnoi zvezdy.
Avtory obsuzhdayut razlichnye idei, pozvolyayushie ob'yasnit' takoi fenomen. Naprimer, "reinkarnaciyu" zvezdy posle sliyaniya (dve slivshiesya nebol'shie zvezdy mogut posle sliyaniya vyglyadet' kak massivnyi ob'ekt). Vozmozhny i drugie ob'yasneniya, svyazannye s vysokoi plotnost'yu zvezd v etoi oblasti, a znachit s vysokoi veroyatnost'yu ih vzaimodeistviya.
Authors: Piotr Popowski, Kem Cook, Andrew Becker
Commets: 24 pages, 2 tables, 7 figures (5 in color), submitted to AJ
Eshe odin "pobochnyi" rezul'tat proekta MACHO - detal'naya karta poglosheniya v napravlenii balzha Galaktiki pokryvayushaya 43 kvadratnyh gradusa nebesnoi sfery. Karta postroena po 9717 opornym tochkam - zvezdam dlya kotoryh izmereno pokrasnenie (po V-R).
Authors: A.M.Ghez et al.
Commets: 7 pages, 5 figures (abridged abstract)
Postroeny orbity eshe neskol'kih zvezd obrashayushihsya vokrug sverhmassivnoi chernoi dyry v centre nashei Galaktiki (predydushie postroeniya sm. zdes'.) Odna iz etih zvezd (S0-16) v 1999 godu proletala na rasstoyanie 60 AU ot chernoi dyry i imela v tot moment skorost' 9000 km/s. Na fotografii oblast' 1"x1" s centrom v Sgr A*.
Authors: Yoshiaki Sofue
Commets: To appear in PASJ, Latex 8 pages, 5 figures, See http://www.ioa.s.u-tokyo.ac.jp/~sofue/htdocs/2003gcs/ for original figures
Predlozhena model', ob'yasnyayushaya poyavlenie obolochek, vidimyh na radiokartah Galakticheskogo centra. Ideya zaklyuchaetsya v povtornyh vspyshkah zvezdoobrazovaniya. Poslednyaya takaya vspyshka dolzhna byla proizoiti okolo 100 000 let nazad. V ramkah toi zhe modeli ob'yasnyayutsya obrazovaniya neskol'ko bol'shego masshtaba, svyazannye s bolee starymi (milliony let) vspyshkami.
O vspyshkah zvezdoobrazovaniya v centre Galaktiki sm. takzhe
astro-ph/0303436
"Stellar disk in the galactic center -- a remnant of a dense accretion
disk?".
Authors: T. Ott et al.
Commets: 19 pages, 7 figures Journal-ref: The Messenger, No 111, p. 1-8 (March 2003)
Pervoe detal'noe opisanie rezul'tatov opticheskih (blizhnii infrakrasnyi diapazon) issledovanii centra Mlechnogo Puti s pomosh'yu adaptivnoi optiki. Avtoram udalos' dostignut' ochen' vysokogo uglovogo razresheniya, a potomu vy imeete udovol'stvie rassmatrivat' eti ochen' krasivye kartinki!
Authors: Yuri Levin, Andrei M. Beloborodov (CITA)
Commets: submitted to ApJ Letters
Eta stat'ya o dvizhenii zvezd vblizi central'noi chernoi dyry v nashei Galaktike. Ob izmerenii ih dvizhenii uzhe soobshalos' (sm. zdes', zdes' ili astro-ph/0303151). Na segodnyashnii den' postroeny 3-mernye orbity dlya 13 zvezd. Vse eti zvezdy dostatochno yarkie i massivnye, sledovatel'no molodye.
Okazyvaetsya 10 iz 13 orbit lezhat pochti v odnoi ploskosti. Avtory predpolagayut, chto oni obrazovalis' iz massivnogo i umerenno tolstogo (s uglom raskrytiya ~10o) akkrecionnogo diska. Sam disk uzhe ne nablyudaetsya - ego veshestvo ne prevrativsheesya v zvezdy uzhe vypalo na chernuyu dyru.
No orbita samoi blizkoi iz zvezd - nazvannoi S2 - naklonena k disku na 75o. Avtory schitayut, chto kogda to i ee orbita lezhala v toi zhe ploskosti, no byla povernuta v segodnyashnee polozhenie precessiei Lenze-Tiringa. Na eto dolzhno bylo uiti 5/a millionov let (0<=a<1 - bezrazmernyi moment vrasheniya chernoi dyry). Esli eto tak, to chernaya dyra v centre Mlechnogo Puti dostatochno bystro vrashaetsya - a>0.2.
Authors: A. Goldwurm et al.
Commets: 8 pages, 5 color figures, 1 table, to be published in Conference Proceedings of the Galactic Center Workshop 2002, November 3-8, 2002, Kailua-Kona, Hawaii, Astron. Nachr., Vol. 324, No. S1 (2003), Special Supplement "The central 300 parsecs of the Milky Way", Eds. A. Cotera, H. Falcke, T. R. Geballe, S. Markoff
Kak izvestno, v centre nashei Galaktiki nahoditsya chernaya dyra s massoi okolo 2 mln. mass Solnca. V radiodiapazone eto istochnik Sgr A*, potomu chasto imenno tak oboznachayut i samu dyru (tochnee, svyazannye s nei istochniki v drugih diapazonah). "Nasha" sverhmassivnaya chernaya dyra ne otnositsya v chislu aktivnyh. Naprimer, v rentgenovskom diapazone - eto ochen' slabyi istochnik. Slabyi, no ne sovsem "mertvyi". Sputnik Chandra uzhe videl rentgenovskie vspyshki Sgr A*. V etoi stat'e avtory predstavlyayut novye dannye po vspyshechnoi aktivnosti Sgr A*, poluchennye na sputnike HMM-N'yuton. Svetimost' istochnika vozrasla za 15 minut v 20 raz. K sozhaleniyu, vspyshka prishlas' na konec seansa nablyudenii. No yasno, chto takaya aktivnost' Sgr A* ne yavlyaetsya redkim yavleniem. Tak chto budut eshe vspyshki.
Publikacii s klyuchevymi slovami:
astrofizika - obzory - ekzoplaneta - Planety u drugih zvezd
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