Kompleks IC342/Maffei
Kompleks IC 342/Maffeinosave
Igor' Drozdovskii
Na peresechenii ekvatora Mestnogo Sverhskopleniya i zony Mlechnogo Puti v shirokih okrestnostyah yarkoi spirali IC 342 raspolagaetsya 12 galaktik s luchevymi skorostyami menee 500 km/s. Sudya po amplitude vnutrennih dvizhenii nekotorye iz nih (Maffei 1, Maffei 2, Dwingeloo 1) yavlyayutsya massivnymi galaktikami, kotorye do nedavnego vremeni ostavalis' nezamechennymi iz-za sil'nogo poglosheniya v Mlechnom Puti. Pomimo izvestnyh ranee v etoi oblasti karlikovyh galaktik: NGC 1560, NGC 1569, UGCA 86, UGCA 92, UGCA 105 za poslednie gody byli obnaruzheny novye ob'ekty: Cas 2 = Dwingeloo 1 (Kraan-Korteweg et al., 1994), Cas1 (Huchtmeier et al., 1995), MB 1 (McCall, Buta, 1995,Huchtmeier, van Driel, 1996), Dwingeloo 2 (Burton et al., 1996), Cam A (Karachentsev, 1994), Cam B (Huchtmeier et al., 1997). Obzory etoi oblasti, sdelannye na plastinkah Tautenburgskogo 2-m teleskopa (Borngen, Karachentseva, 1985) i na kopiyah POSS-II (Karachentseva, Karachentsev, 1997) priveli k obnaruzheniyu eshe dvuh desyatkov kandidatov v chleny etogo blizkogo kompleksa galaktik. Raspredelenie upomyanutyh galaktik v galakticheskih koordinatah predstavleno na ris.1. Galaktiki s ispravlennymi luchevymi skorostyami V0<500 km/s oboznacheny kruzhkami, a veroyatnye novye chleny kompleksa otmecheny krestami.
Za isklyucheniem Maffei 1, Dwingeloo 1, 2 i MB 1, nahodyashihsya v zone samogo sil'nogo poglosheniya, ostal'nye galaktiki s V0<500 km/s uzhe razresheny na otdel'nye zvezdy. Osnovyvayas' na svetimosti yarchaishih golubyh i krasnyh zvezd, byli polucheny sleduyushie ocenki rasstoyaniya do rassmatrivaemyh galaktik: 3.3 Mrs dlya UGCA 105 (Tikhonov et al., 1992), 2.1 Mpc dlya IC342 i 1.9 Mpc dlya UGCA 86 (Karachentsev, Tikhonov, 1993), 3.8 Mpc dlya NGC1560 (Karachentsev et al., 1991), 1.8 Mpc dlya NGC 1569 i 2.2 Mpc dlya UGCA92 (Karachensev et al., 1994), 2.3 Mpc dlya Maffei 2 (Tikhonov, Karachentsev, 1994) i 0.8 Mpc dlya Cas 1 (Tikhonov, 1996). Srednee rasstoyanie galaktik kompleksa IC 342/Maffei po etim dannym, <D>=2.3 Mpc, horosho soglasuetsya s bolee rannimi ocenkami, sdelannymi Spinrad et al. (1973), McCall (1989), no sushestvenno rashoditsya so znacheniem <D>=4.20.5 Mpc, poluchennym Luppino, Tonry (1993) dlya Maffei 1 metodom fluktuacii poverhnostnoi yarkosti.
Problema rasstoyaniya do gruppy IC 342/Maffei 1+2 obsuzhdalas' nedavno Krismer et al. (1996). Ocenivaya modul' rasstoyaniya do NGC 1560 i UGCA 105 po metodu Tully-Fisher, avtory poluchili <D>=(3.60.5) Mpc i pripisali ego vsem ostal'nym galaktikam etoi gruppy. Takoe predpolozhenie ne vyglyadit slishkom ochevidnym v tom sluchae, kogda rasseyannaya associaciya galaktik raspolagaetsya vdol' ekvatorial'noi ploskosti Mestnogo Sverhskopleniya.
Imeya B, V i I PZS snimki 5 galaktik iz kompleksa IC342/Maffei,
poluchennym na teleskope Nordic (NOT) pri kachestve izobrazheniya 0.6 ugl.sek
my proveli DAOPHOT-ALLSTAR fotometriyu ih zvezd.
Na osnove ocenok svetimostei yarchaishih golubyh i krasnyh zvezd my poluchili
sleduyushie rasstoyaniya do galaktik:
3.2 Mpk do UGCA 105, 2.6 Mpk do UGCA 86,
1.8 Mpk do UGCA 92, 1.7 Mpk do NGC 1569
i 1.7 Mpk do Cassiopea 1.
Neobhodimo podcherknut', chto buduchi dostatochno blizkoi, gruppa IC 342/Maffei1+2 mogla sushestvenno vliyat' na traektoriyu galaktik Mestnoi gruppy (Zheng et al., 1991, Valtonen et al., 1993, Peebles, 1994). Poetomu popytki utochnit' rasstoyaniya do rassmatrivaemyh galaktik ostayutsya eshe ves'ma aktual'nymi. Kak bylo upomyanuto ranee, problema chlenstva galaktik v blizkom komplekse IC 342/Maffei ostaetsya nereshennoi iz-za bol'shogo poglosheniya sveta v etoi oblasti i otsutstviya nadezhnyh pryamyh ocenok rasstoyaniya do nekotoryh galaktik. Chtoby sudit' o polnote sushestvuyushih dannyh na tekushii moment, my privodim v tabl.1 osnovnye parametry galaktik v okrestnosti IC 342. Pomimo rassmotrennyh vyshe galaktik my vklyuchili v tablicu ob'ekty, rasstoyaniya i drugie harakteristiki kotoryh izvestny poka s nizkoi tochnost'yu. Takie parametry v tablice otmecheny dvoetochiem. Dlya 12 galaktik, ranzhirovannyh po velichine ih luchevoi skorosti, v stolbcah tabl.1 privedeny sleduyushie dannye:
(1) -- imya galaktiki;
(2) -- izmerennaya luchevaya skorost' (km/s) i skorost', privedennaya k centroidu Mestnoi Gruppy (Karachentsev, Makarov, 1996);
(3) -- standartnyi uglovoi diametr (ugl.min.) i vidimoe otnoshenie osei;
(4) -- integral'naya vidimaya velichina galaktiki i morfologicheskii tip;
(5) -- velichina mezhzvezdnogo poglosheniya sveta i galakticheskaya shirota (grad.);
(6) -- shirina HI linii (km/s) i logarifm HI potoka v ( 10-24 . W/m2);
(7) -- fotometricheskii modul' rasstoyaniya (mag) i rasstoyanie v Mrs; ocenki rasstoyaniya po luchevoi skorosti pri N = 75 km/s/Mrs zaklyucheny v skobki;
(8) -- lineinyi diametr (krs) i absolyutnaya velichina galaktiki s popravkami za naklon soglasno RC3;
(9) -- otnoshenie polnoi massy (v predelah standartnogo diametra) k svetimosti i otnoshenie massy vodoroda k polnoi masse v solnechnyh edinicah;
(10) -- primechaniya otnositel'no istochnika dannyh o rasstoyanii, vidimoi
velichine ili pogloshenii;
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Predstavlennye v tablice dannye mogut byt' polezny pri analize dinamicheskoi situacii v komplekse galaktik vokrug IC 342/Maffei. Ne vdavayas' v detal'noe obsuzhdenie problemy chlenstva galaktik v etom komplekse, otmetim tol'ko dva obstoyatel'stva.
a) Nesmotrya na vozmozhnye sistematicheskie oshibki v opredelenii kak rasstoyaniya galaktiki, tak i velichiny poglosheniya, integral'nye parametry rassmatrivaemyh galaktik v osnovnom sootvetstvuyut ih morfologicheskomu tipu. Isklyuchenie, vozmozhno, sostavlyaet irregulyarnaya galaktika Cas 1 s ee ponizhennym znacheniem otnositel'noi massy vodoroda, a takzhe NGC 1569, u kotoroi otnoshenie polnoi massy k svetimosti vyglyadit anomal'no malym. Takaya pekulyarnost' NGC 1569 privodit k nereal'noi ocenke ee rasstoyaniya (D = 0.78 Mpc) po metodu Tully-Fisher (Krismer et al., 1995).
b) Pri perehode ot normal'nyh spiralei k irregulyarnym karlikovym sistemam metod opredeleniya rasstoyaniya po yarchaishim zvezdam sohranyaet postoyannoi svoyu pogreshnost', okolo 0.4m, (Karachentsev, Tikhonov, 1994). Odnako, tochnost' metoda Tully-Fisher (1977) sushestvenno padaet, kogda on primenyaetsya k galaktikam, u kotoryh amplituda vnutrennego vrasheniya sravnima s ih turbulentnoi skorost'yu. Situaciya usugublyaetsya dlya ob'ektov v zone sil'nogo poglosheniya. Poetomu v rassmatrivaemoi oblasti IC 342/Maffei metod yarchaishih zvezd obladaet nesomnennym preimushestvom pered ispol'zovaniem diagrammy "svetimost'-shirina HI linii".
Zaklyuchitel'nye zamechaniya.
Osnovyvayas' na SSD fotometrii yarchaishego zvezdnogo naseleniya v galaktikah UGCA 105, UGCA 92, UGCA 86 i NGC 1569, my opredelili ih rasstoyaniya, kotorye okazalis' v intervale [1.7-3.3] Mpc. Sravnenie novyh ocenok modulei s prezhnimi (Tikhonov et al., 1992; Karachentsev & Tikhonov, 1993; Karachentsev et al., 1994) pokazyvaet neznachimoe srednee razlichie v modulyah rasstoyanii 0.07m0.26m. Srednyaya kvadratichnaya raznost' ocenok modulei po dvum nezavisimym seriyam izmerenii daet = (0.45m)2, chto sootvetstvuet standartnoi oshibke = 0.32m Takaya pogreshnost' metoda ocenki rasstoyanii horosho soglasuetsya s dannymi analiza Karachenceva i Tihonova (1994), sdelannogo na osnove chlenstva galaktik v blizkih gruppah, i vyglyadit menee pessimistichnoi chem zaklyuchenie Rozanski i Rowan-Robinson'a (1994), rassmatrivavshih preimushestvenno dannye staroi fotograficheskoi fotometrii.
Sushestvuyushie dannye o rasstoyanii IC 342 i okruzhayushih ee sosedei (stolbec 7 tabl.1) eshe ne pozvolyayut sdelat' nadezhnogo zaklyucheniya o prostranstvennoi strukture etogo kompleksa galaktik. My mozhem tol'ko utverzhdat', chto para NGC 1569+UGCA 92 nahoditsya na perednei granice kompleksa. Drugie karlikovye ob'ekty (UGCA 86, NGC 1560, Cam B, UGCA 105) veroyatno associiruyutsya s massivnoi spiral'yu IC 342, a Maffei 1+2 yavlyayutsya vtorym subcentrom protyazhennoi gruppy obshim diametrom okolo 1 Mpc. Situaciya zdes' napominaet druguyu blizkuyu "gruppu" v Skul'ptore, gde na luche zreniya vdol' ploskosti Mestnogo Sverhskopleniya para galaktik NGC 55+NGC 300 proektiruetsya na troinuyu sistemu NGC 253+NGC 247+PGC 2902. Primenenie teoremy viriala dlya ocenki massy takih psevdogrupp obychno privodit k znachitel'nomu zavysheniyu ih real'noi massy.
(Ispol'zovany materialy iz stat'i:
Karachnesev,I., Drozdovsky,I., Kajsin,S., Takalo,L.O., Heinamaki,P, Valtonen,
M,
"Revised photometric distyances to nearby dwarf galaxies in the IC342/Maffei
complex"
A&A Supplement Ser., 1997, v.124, pp.559-571.)
Literatura
- 1 Ables N.D., 1971, Publ. U.S.Naval Obs., 20, part IV, 3
- 2 Arp H., Sandage A., 185, AJ, 90, 1163
- 3 Bajaja E., Huchtmeier W.K., Klein U., 1994, A&A 285, 385
- 4 Börngen F., Karachentseva V.E., 1985, AN, 306, 301.
- 5 Bresolin F., Capaccioli M., Piotto G., 1993, AJ 105, 1779
- 6 Burstein D., Hieles C., 1984, ApJ.Suppl, 54, 33
- 7 Burton W.B., Verheijen M.A., Kraan-Korteweg R.C., Henning P.A., 1996, A&A, 309, 687 (BVKH,96).
- 8 Carignan C. , Beaulieu S., 1989, ApJ 347, 760
- 9 de Vaucouleurs G., 1978, ApJ, 224, 710
- 10 de Vaucouleurs G., de Vaucouleurs A., Corwin H.G., Buta R.J., Paturel G., Fouque P., 1991, Third Reference Catalogue of Bright Galaxies, Springer Verlag. (RC3)
- 11 Georgiev Ts.B., Karachentsev I.D., Tikhonov N.A., 1997, Astronomy Letters 23, 586
- 12 Huchtmeier W.K., Karachentsev I.D., Karachentseva V.E., 1997, A&A (in press) (HKK,97)
- 13 Huchtmeier W.K., Richter O.G., 1986, A&A Suppl., 63, 323
- 14 Huchtmeier W.K., Lercher G., Seeberger R., Saurer W., Weinberger R., 1995, A&A, 293, L33 (HLSSW,95)
- 15 Huchtmeier W.K., van Driel W., 1996, A&A, 305, L25 (HD,96)
- 16 Karachentsev I., 1994, A&Ap Trans., 6, 3
- 17 Karachentsev I.D., Kopylov A.I., Kopylova F.G., 1994, Bull.Spec.Astrophys. Obs. 38, 15
- 18 Karachentsev I.D., Makarov D.I., 1996, AJ, 111, 794
- 19 Karachentsev I.D., Tikhonov N.A., 1993, A&A Suppl., 100, 227 (KT,93)
- 20 Karachentsev I.D., Tikhonov N.A., 1994, A&A, 286, 718
- 21 Karachentsev I.D., Tikhonov N.A., Georgiev Ts.B., Bilkina B.I., Sharina M.E., 1991, A&A Suppl., 91, 503 (KTGBS,91)
- 22 Karachentsev I.D., Tikhonov N.A., Sazonova L.N., 1994, Pis'ma v AZh, 20, 104
- 23 Karachentseva V.E., Karachentsev I.D., 1997 (in preparation)
- 24 Karachentseva V.E., Prugniel Ph., Vennik J., Richter G.M., Thuan T.X., 1996, A&A Suppl, 117, 343
- 25 Karachentseva V.E., Sharina M.E., 1987, Communic. Special Astrophys. Obs., 57, 3
- 26 Kraan-Korteweg R.C., Loan A.J., Burton W.B., Lahav O., Ferguson H., Henning P.A., Lynden-Bell D., 1994, Nature, 372, 77
- 27 Krismer M., Tully R.B., Gioia I.M., 1995, AJ, 110, 1584
- 28 Landolt A.U., 1992, AJ, 104, 340
- 29 Luppino G.A., Tonry J.L., 1993, ApJ, 410, 81
- 30 Makarova L.N., Karachentsev I.D., Georgiev Ts.B., 1997, Astronomy Letters 23, 435
- 31 Makarova L.N., Karachentsev I.D., Takalo L.O., Heinämäki P., Valtonen M., 1998, A&AS (in press)
- 32 McCall M.L., 1989, AJ, 97, 1341
- 33 McCall M.L., Buta R.J., 1995, AJ, 109, 2460 (MB,95)
- 34 O'Connell R.W., Gallagher J.S., Hunter D.A., 1994, ApJ, 433, 65
- 35 Peebles P.J.E., 1994, ApJ, 429, 43
- 36 Piotto G., Capaccioli M., Bresolin F., 1992, Mem. Soc. Astr. Italian, 63, 465
- 37 Sandage A.R., Tammann G.A., 1974, ApJ, 191, 559; 191, 603
- 38 Sandage A.R., Tammann G.A., 1982, ApJ 256, 339
- 39 Sandage A., Bedke J., Atlas of Galaxies Useful for Measuring the Cosmological Distance Scale, 1988, NASA, Washington
- 40 Spinrad H., Bahcall J., Becklin E.E., Gunn J.E., Kristian J., Neugebauer G., Sargent W.L., Smith H., ApJ, 180, 351
- 41 Stetson P.B., 1987, PASP, 99, 191
- 42 Tikhonov N.A., 1996, AN, 317, 175 (T,96)
- 43 Tikhonov N.A., Karachentsev I.D., 1994, Bull.Spatc. Astrophys. Obs., 38, 32 (TK,94)
- 44 Tikhonov N.A., Karachentsev I.D., Bilkina B.I., Sharina M.E., 1992, A&A Trans. 1, 269
- 45 Tikhonov N.A., Karachentsev I.D., 1998 A&A (accepted)
- 46 Tully R.B., Fisher J.R., 1977, A&A, 54, 611
- 47 Valtonen M.J., Byrd G.G., McCall M.L., Innanen K.A., 1993, AJ, 105, 886
- 48 van den Bergh, S., 1966, AJ 71, 922
- 49 Zheng J.Q., Valtonen M.J., Byrd G.G., 1991, A&A, 247, 20
- 2 Arp H., Sandage A., 185, AJ, 90, 1163
Vernut'sya v stat'yu "Mestnoe Sverhskoplenie".
Publikacii s klyuchevymi slovami:
IC 342 - gruppa galaktik - Maffei - blizhaishie galaktiki
Publikacii so slovami: IC 342 - gruppa galaktik - Maffei - blizhaishie galaktiki | |
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