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The R.A.P. Project (Reviews of Astro-Ph) 2003

Metody nablyudenii
(Arhiv Metody nablyudenii:
v.2, 2004, v.1, 2002-2003)

Vypusk 61. 16-30 noyabrya 2003

obzor! astro-ph/0311343 Astrofizicheskie neitrinnye teleskopy (Astrophysical Neutrino Telescopes)
Authors: A.B. McDonald et al.
Comments: 28 pages, 31 figures, Invited review article submitted to Review of Scientific Instruments May 19, 2003

Bol'shoi ponyatnyi obzor po neitrinnym teleskopam (s kartinkami!). Rasskazano o vseh tipah detektorov (solnechnye neitrino, atmosfernye neitrino, neitrino vysokih energii). Kratko daetsya astrofizicheskaya motivaciya dlya raznyh issledovanii. Opisany kak pervye eksperimenty, tak i te, chto tol'ko planiruyutsya.

Ochen' sovetuem vsem, kto hochet uznat' bol'she o neitrinnyh nablyudeniyah.


obzor astro-ph/0311359 Bol'shaya radioastronomiya: sleduyushie 70 let (Large Radio Astronomy: next 70 Years Step)
Authors: Yu.N.Parijskij
Comments: 8 pages, 5 figures, JENAM-2003 conference

Akademik Yurii Nikolaevich Pariiskii pytaetsya predskazat', chto mozhet proizoiti v radioastronomii v blizhaishie desyatiletiya: kakie instrumenty postroyat (nazemnye s ploshad'yu 109 m2, kosmicheskie, ob'edinyat vse chastnye televizionnye antenny), chto budut izuchat' (predely Vselennoi, proto ob'ekty, reliktovoe izluchenie i tela v Solnechnoi sisteme). "No vse eti predskazaniya sil'nee vsego zavisyat ot togo, kakoi deviz vyberet nasha civilizaciya: 'Vpered, k Cheloveku razumnomu' ili 'Nazad k obez'yanam'."


Vypusk 59. 19-31 oktyabrya 2003

astro-ph/0310584 Rezul'taty s Yuzhnogo polyusa, poluchennye na IK teleskope SPIREX (Results from the South Pole InfraRed EXplorer Telescope)
Authors: J.M. Rathborne, M.G. Burton
Comments: 8 pages, 1 figure (low resolution), To appear in the IAU Highlights of Astronomy, Volume 13, Edited by O. Engvold & M. Burton, Published by the Astronomical Society of the Pacific

SPIREX (South Pole InfraRed EXplorer Telescope) - nebol'shoi 60-santimetrovyi teleskop, ustanovlennyi v 1994 g. v Antarktide na stancii Amundsen-Skott. Odnoi iz zadach instrumenta bylo pokazat' na praktike, chto Yuzhnyi polyus yavlyaetsya kraine udobnoi ploshadkoi dlya nablyudenii v IK diapazone. Deistvitel'no, mnogie uchastki v Antarktide nahodyatsya dostatochno vysoko nad urovnem morya, a krome togo tam ochen' holodno.

Avtory privodyat rezul'taty nablyudenii na SPIREX. Konechno, malen'kii instrument ne mozhet tyagat'sya s 8-10-metrovymi gigantami. No ideya sostoit v osnovnom v illyustracii astroklimaticheskih vozmozhnostei Antarktidy dlya nuzhd infrakrasnoi astronomii.


Vypusk 54 23-31 avgusta 2003
astro-ph/0308445 Linzy Frenelya v rentgenovskoi i gamma-astronomii (Fresnel lenses for X-ray and Gamma-ray Astronomy)
Authors: Gerry Skinner et al.
Comments: 12 pages, 7 figures.

Fazovaya linza Frenelya shiroko ispol'zuetsya v astronomicheskoi optike, naprimer, v fotometrii (a takzhe v prozhektorah, v fotografii i t.d.). Ee deistvie osnovano na difrakcii sveta. Esli na puti puchka sveta ot udalennogo istochnika postavit' plastinku i vybrat' tochku za nei (na osi puchka), to samu plastinku mozhno razdelit' na kol'ca (neravnoi tolshiny) dlya kazhdogo iz kotoryh put' lucha sveta do vybrannoi nami tochki otlichaetsya ot sosednih kolec na polovinu dliny svetovoi volny. Eti zony nazyvayutsya "zonami Frenelya". Svetovye volny ot sosednih zon prihodit v vybrannuyu nami tochku v protivofaze i gasyat drug drug. Odnako, esli zakryt' neprozrachnym materialom vse chetnye ili vse nechetnye zony Frenelya, to izluchenie v vybrannuyu tochku budet prihodit' v faze i usilivat'sya. Takim obrazom ploskaya plastina (takie plastinki nazyvayutsya zonnymi) budet vypolnyat' rol' linzy! Odnako v luchshem sluchae v fokuse udastsya sobrat' tol'ko 11% ishodnogo potoka izlucheniya. Esli zhe delat' kol'ca v vide steklyannyh prizm (sm. risunok), to udaetsya sobrat' v tochke prakticheski 100% izlucheniya.

Ustroistvo dvuh variantov zonnyh plastinok (a) i (b) i fazovoi linzy Frenelya (c).

Do poslednego vremeni schitalos', chto sdelat' chto-to podobnoe v zhestkom diapazone (v rentgene i gamma) nevozmozhno. Okazyvaetsya, eto ne tak. Podrobnosti - v stat'e.

Odin iz vozmozhnyh variantov rentgenovskoi difrakcionnoi linzy


astro-ph/0308427 Tekushee sostoyanie detektora "P'er Ozhe" i analiz horosho vosstanavlivaemyh sobytii (Performance of the Pierre Auger Fluorescence Detector and Analysis of well recontructed events)
Authors: Stefano Argiro (for the Pierre Auger Collaboration)
Comments: 4 pages, 3 figures.

V 2001-2002 godah bylo neskol'ko korotkih probnyh zapuskov detektora. V dannoi kratkoi zametke obsuzhdaetsya effektivnost' dannogo pribora i vozmozhnye strategii analiza poluchaemyh s nego dannyh.

Shematicheskoe izobrazhenie elementa detektora "P'er Ozhe"

astro-ph/0308410 Kalibrovka fluorescentnogo detektora "P'er Ozhe" (Calibration of the Pierre Auger fluorescence detector)
Authors: M.D.Roberts, for the Auger Collaboration
Comments: 4 pages, no figures.

"P'er Ozhe" - blizkii v nastoyashee vremya k zaversheniyu ochen' krupnyi atmosfernyi detektor kosmicheskih luchei vysokih energii. Absolyutnaya kalibrovka etogo detektora ochen' vazhnyi element, neobhodimyi dlya pravil'nogo opredeleniya energii registriruemyh chastic. Dlya dannogo instrumenta budet ispol'zovat'sya metod kalibrovki po ravnomerno zasvechennomu polyu s izvestnym svetovym potokom. Krome togo budut ispol'zovat'sya dva nezavisimyh metoda dlya otnositel'noi kalibrovki. V stat'e vy naidete bolee podrobnoe opisanie etih metodov.


Vypusk 53. 10-22 avgusta 2003
astro-ph/0308246 Opticheskaya sistema cherenkovskogo atmosfernogo teleskopa HESS. I. komponenty i komponovka sistemy (The optical system of the H.E.S.S. imaging atmospheric Cherenkov telescopes, Part I: layout and components of the system)
Authors: K. Bernloehr et al.
Comments: 28 pages, 20 figures
astro-ph/0308247 Opticheskaya sistema cherenkovskogo atmosfernogo teleskopa HESS. II. yustirovka zerkal (The optical system of the H.E.S.S. imaging atmospheric Cherenkov telescopes, Part II: mirror alignment and point spread function)
Authors: R. Cornils et al.
Comments: 23 pages, 13 figures

H.E.S.S. (High Energy Stereoscopic System) - stereoskopicheskii atmosfernyi cherenkovskii teleskop dlya registracii chastic sverhvysokih energii.

V etih dvuh stat'yah vy naidete mnogo informacii ob ustroistve ego opticheskoi sistemy.


Vypusk 52. 01-09 avgusta 2003
astro-ph/0308013 Poletnye kalibrovki pribora IBIS/PICsIT (In-flight calibrations of IBIS/PICsIT)
Authors: G. Malaguti et al.
Comments: 5 pages, 7 figures. Accepted for publication on A&A Special Issue on First Science with INTEGRAL

INTEGRAL - nedavno zapushennaya mezhdunarodnaya kosmicheskaya observatoriya, kotoraya s nachala 2003 goda vedet nablyudeniya v zhestkom rentgenovskom i gamma-diapazonah. Na bortu INTEGRAL'a ustanovleno neskol'ko razlichnyh teleskopov. PICsIT (Pixellated Imaging CaeSium Iodide Telescope) - Mnogopiksel'nyi cezii-iodnyi teleskop - rabotayushii v samom zhestkom diapazone detektor teleskopa IBIS. On sostoit iz 4096 nezavisimyh detektorov izlucheniya ploshad'yu 0.7 sm3 kazhdyi, registriruyushih fotony v diapazone energii ot 175 keV do 10 Mev. Etot detektor obladaet ochen' vysokim otnosheniem signal/shum, chto pozvolyaet provodit dlitel'nye (do 105-106 s) nablyudeniya. Odnako parametry, kotorymi budet obladat' teleskop na orbite mogut otlichat'sya ot teh, chto predpolagalis' dlya nego na Zemle. Dlya vyyavleniya etih razlichii sluzhat procedury "kalibrovki na orbite", rezul'tatam kotoryh posvyashena dannaya stat'ya.

Vypusk 50. 8-18 iyulya 2003

astro-ph/0307305 Strategiya scheta fotonov na PZS c nizkim svetovym potokom (Photon counting strategies with low light level CCDs)
Authors: A.G. Basden, C.A. Haniff, C.D. Mackay
Comments: 7 pages, accepted by MNRAS

Redkaya stat'ya, posvyashennaya novomu podklassu detektorov sveta. PZS c nizkim svetovym potokom (L3CCDs = Low light level charge coupled devices) razrabotany dostatochno nedavno. V otlichii ot obychnyh PZS v nih neposredstvenno vnutri chipov proizvoditsya usilenie signala. Odnako usilenie - process stohasticheskii, chto privodit k poyavleniyu zametnogo dopolnitel'nogo shuma. Stat'ya posvyashena sposobam izbavleniya ot nego.

Rekomenduyu etu stat'yu eksperimentatoram i nablyudatelyam, v nei opisan priemnik s novymi, vozmozhno interesnymi imenno dlya vas, svoistvami.



Vypusk 49. 01-07 iyulya 2003

obzor astro-ph/0307036 Opticheskaya interferometriya v astronomii (Optical Interferometry in Astronomy)
Authors: John D. Monnier
Comments: Long Review Article. 86 pages. 31 figures. Arxiv submission size restrictions necessitated heavy compression of figures. Higher quality figures at http://www.astro.lsa.umich.edu/~monnier/Research.html (See http://www.iop.org for final manuscript and copyright notice)
Journal-ref: 2003, Reports on Progress in Physics, 66, 789-857

V poslednih vypuskah my neodnokratno pisali o rezul'tatah, poluchennyh s pomosh'yu interferometricheskoi sistemy VINCI/VLTI. Rabotaet para gigantskih teleskopov im. Keka. Est' mnozhestvo bolee melkih interferometrov v opticheskom diapazone. Vsemu etomu i posvyashen bol'shoi obzor Dzhona Mon'e. Obsuzhdaetsya vse: ot tehnicheskih aspektov do poslednih nauchnyh rezul'tatov i planov po sozdaniyu kosmicheskih interferometrov v optike.


Vypusk 48. 23-30 iyunya 2003


astro-ph/0306408 Poslednie rezul'taty eksperimenta RICE na Yuzhnom polyuse (Recent Results from the RICE Experiment at the South Pole)
Authors: I. Kravchenko, et al.
Comments: Compendium of RICE collaboration submissions to ICRC03

Na nash vzglyad RICE-eto ochen' interesnyi eksperiment. Eto nabor radio antenn, vmorozhennyh v antarkticheskii led. Ih zadacha registrirovat' cherenkovskoe izluchenie ot chastic, porozhdennyh neitrino sverhvysokih energii. Ochen' krasivaya ideya!

V stat'e kratko opisany rezul'taty, kotorye gruppa imeet na dannyi moment na otnositel'no nebol'shoi rabotayushei ustanovke.

Antarkticheskii led - ogromnyi prirodnyi detektor neitrino i kosmicheskih luchei. V etom holodnom krayu uzhe deistvuyut chetyre neitrinnyh detektora: AMANDA (ob etom eksperimente sm. stat'yu astro-ph/0306536), IceCube, ANITA i RICE. Vse oni registriruyut cherenkovskoe izluchenie zaryazhennyh chastic (mezonov), voznikayushih pri soudarenii neitrino s yadrami atomov:

l +N l+N  ,

gde l=e-, -, -. Otlichie eksperimenta RICE ot drugih v tom, chto v nem fiksiruetsya radioizluchenie

V rabote rassmotreny tri voprosa: provedeno Monte-Karlo modelirovanie porozhdeniya radiosignala elektromagnitnym kaskadom vo l'du; utochnen potok i spektr neitrino sverhvysokih energii; izmeren koefficient prelomleniya l'da v prirodnyi usloviyah.

Sleva shema eksperimenta po izmereniyu koefficienta prelomleniya l'da. Peredatchik opuskaetsya v skvazhinu na koaksil'nom kabele. Sprava poluchennyi signal. Glubina razmesheniya peredatchika izmenyalas' s shagom 10 m.

Vypusk 47. 16-21 iyunya 2003

obzor astro-ph/0306383 Interferometricheskie nablyudeniya reliktovogo izlucheniya (Interferometric Observations of the Cosmic Microwave Background Radiation)
Authors: A. C. S. Readhead, T. J. Pearson
Comments: To appear in Carnegie Observatories Astrophysics Series, Vol. 2: Measuring and Modeling the Universe, ed. W. L. Freedman (Cambridge: Cambridge Univ. Press); 21 pages; low-quality figures

Radiointerferometry uzhe horosho zarekomendovali sebya pri nablyudenii reliktovogo fona. Oni prekrasno rabotayut na malyh uglovyh masshtabah, pri etom dannye pribory pozvolyayut registrirovat' kak polnyi potok radiacii, tak i ee polyarizaciyu.


Shema radiointerferometra

Na segodnyashnii den' deistvuyut tri interferometricheskih ustanovki dlya issledovaniya kosmicheskogo mikrovolnovogo fona: CBI - Cosmic Background Imager (ustanovlen na vysote 5080 m v Chiliiskih Andah), DASI - Degree Angular Scale Interferometer (ustanovlen na yuzhnom polyuse) i VSA - Very Small Array (na observatorii Tenerif). Parametry ustanovok dostatochno pohozhi. V obzore vy naidete ih podrobnoe opisanie, a takzhe teoriyu nablyudenii na podobnyh interferometrah.


Vneshnii vid interferometra CBI

Vypusk 45. 26-31 maya 2003

katalog astro-ph/0305535 Gamburgskii katalog opticheskoi identifikacii yarkih ob'ektov ROSAT (The Hamburg/RASS Catalogue of optical identifications. Northern high-galactic latitude ROSAT Bright Source Catalogue X-ray sources)
Authors: F.-J. Zickgraf, D. Engels, H.-J. Hagen, D. Reimers, W. Voges
Comments: 20 pages, 23 figures, accepted for publication in Astronomy & Astrophysics

Sravnenie togo, kak kakoi-to istochnik vyglyadit v raznyh diapazonah (v nashem primere - v rentgene i v optike) - osnova interpretacii nablyudenii v segodnyashnei astrofizike. I dannyi katalog - bol'shoe tomu podspor'e. V kataloge predstavlen 5341 otozhdestvlennyi yarkii istochnik iz kataloga rentgenovskoi kosmicheskoi observatorii ROSAT na severnom nebe. 42% istochnikov - aktivnye yadra galaktik, 31% - zvezdy i dvoinye sistemy, 4% - galaktiki, 5% - skopleniya galaktik.

astro-ph/0305492 Pervaya versiya Sloanovskogo cifrovogo obzora neba (The First Data Release of the Sloan Digital Sky Survey)
Authors: The SDSS collaboration (Kevork Abazajian et al.)
Comments: 16 pages. Submitted to The Astronomical Journal.

Poyavilas' pervaya obshedostupnaya versiya odnogo iz samyh grandioznyh astrofizicheskih obzorov! (Hochetsya postavit' vosklicatel'nyi znak posle kazhdogo slova.)

V etu pervuyu versiyu voshli dannye obzora 2099 kvadratnyh gradusov neba (eto eshe ochen' malo po sravneniyu s polnoi ploshad'yu neba - primerno 44 000 kv. gradusov) v pyati fil'trah (u, g, r, i, z). V nih soderzhatsya izobrazheniya i spektry 186,240 ob'ektov (kvazarov, galaktik i zvezdy), a takzhe fonovye ploshadki dlya kalibrovok. Polucheny izobrazheniya ob'ektov do 22.6 velichiny (v fil'tre r) s tochnost'yu fotometrii poryadka dvuh procentov i tochnost'yu koordinat poryadka odnoi desyatoi uglovoi sekundy. Spektry ob'ektov polucheny v intervale 3800-9200 angstrem. Dopolnitel'nye svedeniya mozhno naiti v stat'e ili na saite http://www.sdss.org/dr1.


Oblasti neba, dannye o kotoryh uzhe opublikovany

Vypusk 40. 20-25 aprelya 2003

astro-ph/0304364 Poisk bystryh radiotranzientov (Searches for Fast Radio Transients)
Authors: J. M. Cordes, M. A. McLaughlin
Comments: 12 pages, Submitted to ApJ

Obsuzhdaetsya ideal'naya metodika poiska bystryh tranzientnyh (vspyshechnyh) sobytii v radiodiapazone. Istochnikov takih vspleskov mozhet byt' ochen' mnogo: ot radiopul'sarov do gamma-vspleskov, ot dzhetov v aktivnyh yadrah galaktik i tesnyh dvoinyh sistemah do vnezemnyh civilizacii.

Iskat' korotkie impul'sy v radiodiapazone osobenno trudno iz-za vliyaniya mezhzvezdnoi sredy na rasprostranenie signala. Imenno etu problemu avtory obsuzhdayut osobenno detal'no. Krome togo, vo vvedenii privoditsya nebol'shoi obzor po poisku korotkih tranzientnyh yavlenii v radiodiapazone.

Mozhno ozhidat', chto vvedenie v stroi novyh mnogopuchkovyh sistem radioteleskopov pozvolit sushestvenno prodvinut'sya v issledovanii bystryh radiotranzientov. Vvedenie zhe v stroi kilometrovoi antennoi reshetki (SKA) privedet k nastoyashemu proryvu v etoi oblasti.


astro-ph/0304334 Avtomaticheskoe detektirovanie rasshiryayushihsya obolochek HI s pomosh'yu neironnyh setei (Automatic Detection of Expanding HI Shells Using Artificial Neural Networks)
Authors: Anik Daigle et al.
Commnets: 39 pages, 11 figures, accepted by PASP

V segodnyashnei astronomii ochen' chetko proslezhivayutsya dve tendencii - pervaya iz nih - razrabotka i sozdanie vse bolee slozhnyh i sovershennyh instrumentov (ogromnye nazemnye teleskopy s aktivnoi optikoi, kosmicheskie teleskopy i observatorii s detektorami ogromnyh ploshadei, s vysochaishim vremennym i spektral'nym razresheniem, radioteleskopy ploshad'yu v 1 km2, detektory kosmicheskih luchei ob'emom 1 km3 i t.d.). Eti instrumenty ostro nuzhny dlya provedeniya issledovanii na peredovyh rubezhah sovremennoi astrofiziki i kosmologii. S drugoi storony, ochen' bol'shoe kolichestvo uzhe poluchennyh nablyudatel'nyh materialov, dazhe na peredovyh instrumentah i v luchshih observatoriyah, ostaetsya neobrabotannym. Poetomu tak chasto v publikaciyah vstrechayutsya frazy "otkrytie sdelannoe na sputnike BBB bylo zatem(!) podtverzhdeno po arhivnym dannym sputnika AAA". Na samom dele eta fraza oznachaet, chto dannoe otkrytie moglo byt' sdelano na neskol'ko let ran'she, no ne hvatilo lyudei, vremeni, sil.

Edinstvennym real'nym vyhodom iz dannoi situacii yavlyayutsya sistemy avtomaticheskoi obrabotki nablyudenii. Postepenno oni, po-vidimomu, poyavyatsya vo vseh napravleniyah nablyudatel'noi astronomii, a poka nachinayut deistvovat' tam, gde idet massovoe nablyudenie kakih libo ob'ektov - primerami yavlyayutsya poiski gravitacionnogo mikrolinzirovaniya (neskol'ko millionov zvezd, trebuyushih obrabotki, v odnom kadre), vspyshek sverhnovyh v dalekih galaktikah, avtomaticheskoe vyyavlenie i klassifikaciya peremennyh zvezd, opredelenie krasnyh smeshenie galaktik v cifrovyh obzorah i t.d.

V dannoi stat'e rassmatrivaetsya algoritm avtomaticheskogo obnaruzheniya rasshiryayushihsya obolochek neitral'nogo vodoroda (H I). Esli otdelyat' takuyu obolochku ot fona tol'ko po ee forme, to zadacha okazyvaetsya ochen' slozhnoi - forma obolochki mozhet byt' pochti lyubaya. Bolee prostym naiti reshenie, esli obolochka rasshiryaetsya. Togda snachala ishutsya osobennosti spektra izlucheniya obolochki, svyazannye (iz-za effekta Dopplera) s ee rasshireniem. Takoi analiz proizvoditsya dlya kazhdogo pikselya izobrazheniya. Esli takie tochki obrazuyut gruppy, to eti mesta otmechayutsya kak naibolee perspektivnye dlya dal'neishego issledovaniya v linii 21 sm vodoroda.


Vypusk 39. 12-18 aprelya 2003

miniobzor astro-ph/0304230 Izobrazheniya s vysokim razresheniem - passivnyi i aktivnyi podhod (High resolution imaging by employing passive and active approaches)
Authors: Swapan K. Saha
Comments: 20 pages LaTeX file including 13 figures

Zemnaya atmosfera, tochnee ee neodnorodnosti, prepyatstvuyut dostizheniyu vysokogo uglovogo razresheniya, chto ochen' sil'no meshaet nablyudat' slabye istochniki i ob'ekty so slozhnoi melkomasshtabnoi strukturoi. Radikal'nyi sposob resheniya problemy - vynos instrumenta v kosmos - ochen' ochen' dorog. Na Zemle s etoi problemoi mozhno borot'sya dvumya putyami. S pomosh'yu aktivnoi optiki, kotoraya otslezhivaet i kompensiruet vozmusheniya volnovogo fronta, vyzyvaemye atmosferoi. Drugoi (passivnyi) sposob - spekl-interferometriya. Esli sdelat' fotografiyu tochechnogo istochnika, "isporchennogo" atmosferoi, s ochen' korotkoi ekspoziciei, to my uvidim, chto ono sostoit iz bol'shogo chisla otdel'nyh izobrazhenii - speklov, kazhdoe iz kotoryh obladaet vysokim razresheniem. Esli ih pravil'no slozhit', mozhno poluchit' horoshee izobrazhenie i na Zemle.

V dannoi stat'e obsuzhdayutsya preimushestva odnogo i drugogo podhodov, kotorye illyustriruyutsya na real'nyh instrumentah.


(Arhiv Metody nablyudenii:
v.2, 2004, v.1, 2002-2003)

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