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12.07.02. astro-ph za 8-12 iyulya 2002 goda: izbrannye stat'i |
Kak izvestno, mnogie ekzoplanety imeyut ellipticheskie orbity.
Avtor stat'i pokazyvaet, chto v esli v sisteme dvuh planet,
obladayushih pervonachal'no krugovymi orbitami, vozmutit'
orbitu odnoi iz planet, to i vtoraya priobretet zametnyi ekscentrisitet.
Poluchivshayasya v rezul'tate sistema budet ochen' pohozha na nekotorye iz
nablyudaemyh ekzoplanetnyh sistem.
Authors: C.G. Tinney et al. Comments: 10 pages, 5 figures and 5 tables V stat'e rasskazyvaetsya ob otkrytii 4 vnesolnechnyh planet okolo zvezd, bogatyh metallami (HD73526, HD76700, HD30177 i HD2039).
Planeta, vrashayushayasya vokrug HD 76700 (krugovaya orbita, period okolo 4 dnei),
obladaet odnoi iz samyh malen'kih mass: poryadka 0.7 massy Saturna.
Drugie planety imeyut periody ot 190 dnei do 4.4 let i bolee tipichnye
massy.
Author: Bertil Dorch Comments: Invited review, IAU coll. 188: Magnetic coupling of the solar atmosphere
V obzore rassmatrivaetsya trehmernoe modelirovanie magnitnyh trubok na
Solnce. Obsuzhdayutsya razlichnye neustoichivosti v trubkah, a takzhe nereshennye
problemy.
Authors: A. Udalski et al. Comments: 7 pages, Latex. Appendix in 'jpg' format. Full resolution pages of Appendix and photometric data presented in the paper are available from the OGLE Internet archive: http://www.astrouw.edu.pl/~ogle or its US mirror http://bulge.princeton.edu/~ogle Journal-ref: Acta Astronomica (2002) 52, 115 V stat'e predstavleny novye rezul'taty, poluchennye posle pereobrabotki dannyh nablyudenii proekta OGLE-III za 2001 god. Ispol'zuyutsya fotometricheskie dannye, kotorye pozvolyayut obnaruzhit' sputnik u zvezdy, esli on prohodit po ee disku, t.k. v etom sluchae blesk zvezdy oslablyaetsya (oslablenie men'she 0.08 zvezdnoi velichiny). Rassmatrivayutsya malomassivnye ob'ekty (karlikovye zvezdy, korichnevye karliki, "yupitery"). Privodyatsya podrobnye dannye po 13 novym ob'ektam (eto yavlyaetsya dopolneniem k katalogu iz 46 ob'ektov, opublikovannomu ranee). Vozmozhno, odin iz novyh ob'ektov imeet massu poryadka massy Saturna (dlya tochnogo opredeleniya massy sputnika nedostatochno fotometricheskih nablyudenii, poetomu tut trebuetsya i spektroskopiya dlya izmereniya variacii luchevoi skorosti zvezdy, odnako v dannoi rabote vyvody osnovyvayutsya tol'ko na dvuhcvetnoi (I, V) fotometrii). Tipichnye oribital'nye periody - dni. Vsego seichas v eksperimente OGLE otkryto 59 sistem, gde malomassivnyi sputnik prohodit po disku zvezdy. Takzhe privodyatsya novye dannye (iyun' 2002 g.) po sobytiyam OGLE-TR-10 i OGLE-TR-40 (eto nailuchshie kandidaty v planety, obnaruzhennye dannym metodom).
Sm. takzhe stat'yu S. Dreizler et al. "Spectral Types of Planetary Host Star
Candidates: Two New Transiting Planets?"
astro-ph/0207192,
gde obsuzhdayutsya spektral'nye nablyudeniya nekotoryh iz pervyh 46 sistem..
Authors: A. Goobar et al. Comments: 9 pages, 9 figures, accepted for publication in A&A Avtory issleduyut vozmozhnost' opredeleniya kosmologicheskih parametrov po nablyudeniyam linzirovannyh sverhnovyh. Takie nablyudeniya stanut obychnym delom s zapuskom novyh kosmicheskih apparatov SNAP i NGST. S pomosh'yu etih sputnikov mozhno budet nablyudat' sotni sverhnovyh s mnozhestvennymi izobrazheniyami (t.e. iz-za linzirovaniya budet vidno neskol'ko izobrazhenii odnogo istochnika). Tochnye izmereniya uglovogo rasstoyaniya mezhdu izobrazheniyami, otnosheniya potokov ot raznyh izobrazhenii i vremennoi zaderzhki pozvolyat poluchat' dannye o kosmologicheskih parametrah.
Avtory obsuzhdayut istochniki sistematicheskih oshibok.
Author: J. Patrick Henry Comments: 16 pages, 11 figures, invited review at the conference Matter and Energy in Clusters of Galaxies Seichas blagodarya sputnikovym nablyudeniyam v rentgenovskom diapazone my imeem bol'shoe kolichestvo informacii o skopleniyah galaktik. V obzore rassmatrivaetsya evolyuciya svetimosti skoplenii galaktik v rentgenovskom diapazone, a takzhe evolyuciya temperatury gaza v skoplenii (sm. takzhe segodnyashnyuyu stat'yu W. Forman et al. "Galaxy Clusters with Chandra" astro-ph/0207165).
Authors: J. M. Cordes and T. J. W. Lazio Comments: 21 pages, 16 figures, instructions for downloading software Kak opredelyayut rasstoyaniya do dalekih radiopul'sarov? Dlya etogo ispol'zuyut t.n. meru dispersii. Potom, znaya raspredelenie elektronov po luchu zreniya poluchayut rasstoyanie. No otkuda my berem raspredelenie elektronov? Imenno iz takih statei kak eta!
Predydushaya model' raspredeleniya byla dana v 1993 g. Teilorom i Kordesom.
Togda prishlos' sushestvenno peresmotret' rasstoyaniya do pul'sarov v storonu
uvelicheniya, chto privelo, sootvetstvenno, k uvelicheniyu ih skorostei
i obostreniyu problemy "skorosti otdachi" pri rozhdenii neitronnyh zvezd.
Novaya model' ne vedet k takim revolyucionnym preobrazovaniyam. Odnako,
dlya nekotoryh ob'ektov rasstoyanie dolzhno byt' sushestvenno peresmotreno.
Author: T. Bloecker Comments: 8 pages, 4 postscript figures, also available from http://www.mpifr-bonn.mpg.de/div/ir-interferometry; invited review at IAU Symp. 209 "Planetary Nebulae", ASP, in press
Rassmatrivaetsya struktura i evolyuciya central'nyh zvezd planetarnyh
tumannostei. Eti zvezdy prohodyat korotkuyu stadiyu evolyucii mezhdu
asimptoticheskoi vetv'yu gigantov i belymi karlikami. Perehod k stadii
belogo karlika opredelyaetsya vnutrennei strukturoi zvezdy, kotoraya v svoyu
ochered' opredelyaetsya predydushei istoriei zvezdy, v pervuyu ochered'
evolyuciei na asimptoticheskoi vetvi gigantov, a takzhe posleduyushei poterei
massy.
Author: F. Krennrich et al. Comments: 24 pages, 3 figures, submitted May 20 2002, accepted for publication in the Astrophysical Journal Letters Otkryta spektral'naya peremennost' gamma-blazara Mrk 421 v TeVnom diapazone. Nablyudeniya provodilis' na 10-metrovom teleskope observatorii Whipple.
Etot istochnik sil'no peremenen (faktor 30).
Spektr izuchalsya v diapazone ot 380 GeV do 8.2 TeV.
Spektry horosho opisyvayutsya stepennym zakonom s eksponencial'nym zavalom.
Polozhenie zavala ne menyalos', zato izmenyalsya spektral'nyi indeks
ot 1.89 do 2.72. Est' korrelyaciya mezhdu izmeneniyami spektra
i svetimosti.
Author: Martin White Comments: 14 pages, 12 figures, to appear in ApJS
Odnim iz naibolee vazhnyh predskazanii lyuboi teorii obrazovaniya
krupnomasshtabnoi struktury yavlyaetsya kolichestvo ob'ektov
razlichnoi massy. V takih modelyah pod ob'ektom obychno
podrazumevaetsya galo temnoi materii.
Avtor podrobno obsuzhdaet
funkciyu mass galo v razlichnyh kosmologicheskih
modelyah.
Author: Jon Loveday, for the SDSS collaboration Comments: 20 pages, review to appear in Contemporary Physics Report-no: CP 02.5/13
Podrobno opisan Sloanovskii Cifrovoi Obzor Neba.
Sut' proekta - postroenie mnogocvetnoi trehmernoi karty raspredeleniya
galaktik. Nablyudeniya provodilis' v pyati cvetah: ot blizhnego UF do blizhnego
IK. Baza dannyh budet soderzhat' okolo 50 millionov galaktik
do 23 zvezdnoi velichiny (predel razlichen v raznyh cvetah).
Zatem budut polucheny spektry 1 milliona galaktik i 100 000 kvazarov.
Proekt rabotaet uzhe dva goda, sootvetstvenno v obzore obsuzhdayutsya
rezul'taty, poluchennye za eto vremya.
Author: Max Tegmark Comments: Invited review for Science, 4 figs. Slightly abbreviated published version available at http://www.hep.upenn.edu/~max/spacetime.html
Populyarnyi obzor sovremennoi kosmologii.
Opisyvaetsya standartnaya na segodnyashnii den' model'
(65 procentov temnoi energii, 30 procentov holodnogo temnogo veshestva).
Author: Samuel M Leach, Andrew R Liddle Comments: 6 pages LaTeX file with figures incorporated. Slow-roll inflation module for use with the CAMB program can be found at http://astronomy.cpes.susx.ac.uk/~sleach/inflation/
Issleduyutsya ogranicheniya na parametry inflyacionnoi modeli,
sleduyushie iz nablyudenii reliktovogo izlucheniya.
Avtory polagayut, chto s uluchsheniem tochnosti nablyudenii
metod, predlagaemym imi mozhet stat' dominiruyushim v opredelenii parametrov
inflyacionnogo scenariya.
Author: T. Di Salvo, L. Stella Comments: 11 pages, including 4 figures. To appear in the proceedings of the XXII Moriond Astrophysics Meeting "The Gamma-Ray Universe" (Les Arcs, March 9-16, 2002), eds. A. Goldwurm, D. Neumann, and J. Tran Thanh Van, The Gioi Publishers (Vietnam)
Daetsya obzor sovremennogo sostoyaniya del v izuchenii zhestkogo rentgenovskogo
izlucheniya ot malomassivnyh rentgenovskih
dvoinyh sistem.
Provoditsya sravnenie sistem s neitronnymi zvezdami i chernymi dyrami.
Obsuzhdayutsya perspektivy, svyazannye s zapuskom sputnika INTEGRAL
(napomnim, chto 25 procentov nablyudatel'nogo vremeni na etom apparate
prinadlezhit Rossii).
Author: G.G.Raffelt Comments: Contribution to Dennis Sciama Memorial Volume of NAR
Nesmotrya na otkrytie neitrinnyh oscillyacii sobstvenno massy neitrino
ostayutsya neizvestnymi. V stat'e obsuzhdayutsya kosmologicheskie predely na
massy neitrino (naibolee sil'nyi seichas sleduet iz obzora krasnyh smeshenii
galaktik 2dF vkupe s teoriei obrazovaniya krupnomasshtabnoi struktury).
Takzhe obsuzhdaetsya vozmozhnaya rol' neitrino v obrazovanii kosmicheskih luchei
vysokih energii.
Author: A. Sozzetti et al. Comments: 47 pages, 9 figures, to appear in the Publications of the Astronomical Society of the Pacific (November 2002) Kak mozhno iskat' vnesolnechnye planety? Po smesheniyu linii v spektre zvezdy, po analogichnomu effektu dlya impul'sov radiopul'sarov, po umen'sheniyu bleska zvezdy (esli planeta prohodit po disku)... A eshe? A eshe - po astrometricheskim dannym! Avtory stat'i polagayut, chto budushie astrometricheskie sputniki pozvolyat otkryt' do 95 procentov (!) planet s periodami ot dnei do neskol'kih let (verhnii predel - poryadka vremeni zhizni sputnika). Konechno, rech' idet ne o vseh planetah voobshe, a o planetah vokrug zvezd, dostupnyh dlya sputnika.
Avtory opisyvayut metodiku opredeleniya parametrov orbit i t.p.
Predlagayutsya raznye nablyudatel'nye strategii.
Author: Sultana N. Nahar Comments: 15 pgs., 5 color figs., Invited Review, Proceedings of the Workshop on Stellar Atmosphere Modeling, Tuebingen, Germany, April 8-12, 2002 12 iyulya v astro-ph poyavilos' srazu tri raboty etogo avtora, posvyashennye atomnoi fizike. V dannom obzore avtor opisyvaet poslednie dostizheniya v vychislenii neprozrachnostei, chto yavlyaetsya chrezvychaino aktual'nym dlya astrofiziki (zvezdnye atmosfery, tumannosti, aktivnye yadra galaktik i t.d.).
Krome osnovnyh fizicheskih processov, sushestvennyh dlya dannyh vychislenii,
i prochei "kuhni" avtor opisyvaet onlainovye bazy dannyh i dostupnye kody
dlya sootvetstvuyushih vychislenii.
Author: Heino Falcke, Peter Gorham Comments: Astropart. Phys., in press, LaTex (elsart.cls included), 29 pages, 4 figures, also available at http://www.mpifr-bonn.mpg.de/staff/hfalcke/publications.html#lofarpaper Oh uzh eti kosmicheskie luchi sverhvysokih energii! Vse hotyat ih registrirovat'. Pri etom metodiki mogut byt' raznymi. Naprimer, mozhno pytat'sya nablyudat' radioizluchenie. Ideya v izluchenii, sozdavaemom elektron-pozitronnymi parami, dvizhushimisya v zemnom magnitnom pole. Dlya takih nablyudenii nuzhny novye instrumenty. Takim budet teleskop LOFAR (Low-Frequency Array), rabotayushii na 10-200 MHz. Uzhe sushestvuet prototip: LOPES. V otdalennom budushem poyavit'sya kilometrovaya reshetka (Square-Kilometer-Array SKA). Eto eshe bolee moshnyi instrument. LOFAR budet videt' livni ot kosmicheskih luchei s energiei ot 2*10^14 eV do ~10^20 eV.
Author: V.V. Flambaum Comments: 2 pages, RevTex "Est' li zhizn' na Marse, net li zhizni na Marse. Nauke eto neizvestno, nauka poka ne v kurse dela".
Ochen' korotkaya polemicheskaya zametka v otvet na stat'yu lyudei, schitayushih, chto
zhizn' vo Vselennoi eto obychnoe delo.
Author: Mordehai Milgrom Comments: 21 pages, Submitted to New Astr. Review. Based on a talk presented at the MOND workshop, Paris, October 2001
Kto skazal, chto sovremennaya nauka pogryazla sama v sebe?
Vot, naprimer
MOND
- Modified Newtonian Dynamics.
Teoriya yavlyaetsya al'ternativoi temnoi materii.
Al'ternativa plohaya, opisyvaet tol'ko chast' effektov, a chto delat' s
ostal'nymi ne znaet. No tem ne menee. Diskussii idut...
Author: Lawrence M. Widrow Comments: 67 pages, 17 figures, accepted for publication in Reviews of Modern Physics My znaem kak mozhno usilit' magnitnoe pole (dinamo). No dlya etogo nuzhno chtoby bylo chto usilivat'. V obzore obsuzhdaetsya kak teoriya dinamo v galaktikah, tak i proishozhdenie zachatochnogo (seed) polya v rannei Vselennoi.
Detal'no opisyvayutsya sovremennye nablyudeniya.
Author: R.Fusco-Femiano et al. Comments: 15 pages, 9 figures, Invited Review : "Matter and Energy in Clusters of Galaxies", 23-27 April 2002, Taiwan, ASP, Conf. Ser., eds: S.Bowyer & C-Y.Hwang
Sputnik BeppoSAX - horoshii primer nedorogogo i ochen' uspeshnogo proekta.
V obzore opisyvayutsya nablyudeniya skoplenii galaktik na etom apparate.
Author: Maurice H.P.M. van Putten Comments: To appear in ApJ Lett
Obsuzhdaetsya vozmozhnost' registracii gravitacionnogo izlucheniya ot tora,
obrazuyushegosya vokrug chernoi dyry posle vspyshki gipernovoi.
Avtor polagaet, chto izluchenie ot blizkih vzryvov mozhet byt' zaregistrirovano
uzhe na LIGO/VIRGO.
Author: Jong-Hak Woo, C. Megan Urry Comments: 43 pages with 10 figures. Accepted for publication in ApJ Kak vy dumaete, skol'ko sushestvuet horoshih ocenok mass dlya sverhmassivnyh chernyh dyr? 117! V stat'e avtory analiziruyut dannye po vsem etim ob'ektam. Dopolnitel'no privodyatsya 200 ocenok mass chernyh dyr, poluchennye po svoistvam baldzhei galaktik (sushestvuet dovol'no horoshee sootvetstvie mezhdu massoi dyry i massoi baldzha). Avtory prihodyat k vyvodu, o tom, chto mnogie korrelyacii ne tak uzh i horoshi. Naprimer, net korrelyacii mezhdu massoi chernoi dyry i svetimost'yu galaktiki.
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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