HI in the field of the dwarf spheroidal/irregular galaxy Phoenix

被引:47
作者
St-Germain, J
Carignan, C
Côte, S
Oosterloo, T
机构
[1] Univ Montreal, Dept Phys, Montreal, PQ H3C 3J7, Canada
[2] Univ Montreal, Observ Mt Megant, Montreal, PQ H3C 3J7, Canada
[3] Natl Res Council Canada, Herzberg Inst Astrophys, Dominion Astrophys Observ, Victoria, BC V8X 4M6, Canada
[4] Netherlands Fdn Res Astron, NL-7990 Dwingeloo, Netherlands
关键词
galaxies : dwarf galaxies : individual (Phoenix dwarf) ISM : HI; Local Group; techniques : interferometric;
D O I
10.1086/301021
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
New results are presented for a mosaic mapping of the H I in the field of the Local Group dwarf galaxy Phoenix. The observations, obtained with the Australia Telescope Compact Array, cover an area of similar to 2 degrees x 2 degrees. Four velocity components are identified, at heliocentric velocities of -23, 7, 59, and 140 km s(-1). While the gas at 7 km s(-1) is of Galactic origin and the gas at 140 km s(-1) is most likely associated with the Magellanic Stream, the situation for the two other components is unsure. However, it is suggested that the component at -23 km s(-1) is probably associated with Phoenix because: (1) it has a compact structure and is only slightly offset from the optical image, (2) its H I mass of similar to 10(5) M. is what can be expected in such a system, 3) it has a definite velocity gradient, (4) its location west of Phoenix is compatible with the already suspected self-propagation from east to west of the last star formation episode. Because of the large mass (similar to 5 x 10(6) M.) implied if at the distance of Phoenix and also because of its large extent, the component at +59 km s(-1) is most likely not associated. Optical velocities are still needed to confirm or not those possible associations.
引用
收藏
页码:1235 / 1244
页数:10
相关论文
共 27 条
[1]   THE HI CONTENT OF THE LOCAL GROUP DWARF (SPHEROIDAL OR IRREGULAR QUESTIONABLE) GALAXY PHOENIX [J].
CARIGNAN, C ;
DEMERS, S ;
COTE, S .
ASTROPHYSICAL JOURNAL, 1991, 381 (01) :L13-L16
[2]   Detection of H I associated with the Sculptor dwarf spheroidal galaxy [J].
Carignan, C ;
Beaulieu, S ;
Cote, S ;
Demers, S ;
Mateo, M .
ASTRONOMICAL JOURNAL, 1998, 116 (04) :1690-1700
[3]   DWARF ELLIPTIC GALAXIES [J].
FERGUSON, HC ;
BINGGELI, B .
ASTRONOMY AND ASTROPHYSICS REVIEW, 1994, 6 (1-2) :67-122
[4]   DWARF SPHEROIDAL GALAXIES - KEYSTONES OF GALAXY EVOLUTION [J].
GALLAGHER, JS ;
WYSE, RFG .
PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF THE PACIFIC, 1994, 106 (706) :1225-1238
[5]  
GREBEL EK, 1998, IAU S, V192, P1
[6]   VELOCITY STRUCTURE IN THE MAGELLANIC STREAM [J].
HAYNES, MP .
ASTRONOMICAL JOURNAL, 1979, 84 (08) :1173-1188
[7]   The star formation history of the Carina dwarf galaxy [J].
Hurley-Keller, D ;
Mateo, M ;
Nemec, J .
ASTRONOMICAL JOURNAL, 1998, 115 (05) :1840-1855
[8]   Structural parameters for the Galactic dwarf spheroidals [J].
Irwin, M ;
Hatzidimitriou, D .
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 1995, 277 (04) :1354-1378
[9]  
KARACHENTSEV ID, 1996, AJ, V111, P796
[10]  
LIN D, 1999, IN PRESS P 33 RENC M