2007ApJ...662L..79C

Query : 2007ApJ...662L..79C

2007ApJ...662L..79C - Astrophys. J., 662, L79-L82 (2007/June-3)

Strangers in the night: discovery of a dwarf spheroidal galaxy on its first Local Group infall.

CHAPMAN S.C., PENARRUBIA J., IBATA R., McCONNACHIE A., MARTIN N., IRWIN M., BLAIN A., LEWIS G.F., LETARTE B., LO K., LUDLOW A. and O'NEIL K.

Abstract (from CDS):

We present spectroscopic observations of the And XII dwarf spheroidal galaxy using DEIMOS/Keck II, showing it to be moving rapidly through the Local Group (-556 km/s heliocentric velocity, -281 km/s relative to Andromeda), falling into the Local Group from ∼115 kpc beyond Andromeda's nucleus. And XII therefore represents a dwarf galaxy plausibly falling into the Local Group for the first time and never having experienced a dense galactic environment. From Green Bank Telescope observations, a limit on the H I gas mass of <3x10³ M_☉ suggests that And XII's gas could have been removed prior to experiencing the tides of the Local Group galaxies. Orbit models suggest that the dwarf is close to the escape velocity of M31 for published mass models. And XII is our best direct evidence for the late infall of satellite galaxies, a prediction of cosmological simulations.

Abstract Copyright: ∼

Journal keyword(s): Galaxies: Evolution - galaxies: individual (Andromeda) - Galaxies: Spiral - Galaxies: Local Group

Nomenclature: Table 1: [CPI2007] JHHMMSS.ss+DDMMSS.s N=8.

Simbad objects: 35

Full paper

View the references in ADS

Number of rows : 35

N	Identifier	Otype	ICRS (J2000) RA	ICRS (J2000) DEC	Mag U	Mag B	Mag V	Mag R	Sp type	#ref 1850 - 2026	#notes
1	IC 10	rG	00 20 17.33520	+59 18 13.6480		13.6	9.5		~	1185	1
2	NGC 147	GiG	00 33 12.120	+48 30 31.46		12.0	9.5		~	720	1
3	NAME Andromeda III	G	00 35 33.8	+36 29 52			14.4		~	309	0
4	NGC 185	Sy2	00 38 57.9400026024	+48 20 15.035874648		9.10	9.2		~	840	1
5	M 110	GiG	00 40 22.0572349992	+41 41 07.507220136		8.92	8.07		~	1370	1
6	M 32	GiG	00 42 41.82480	+40 51 54.6120	9.51	9.03	8.08		~	2236	2
7	M 31	AGN	00 42 44.330	+41 16 07.50	4.86	4.36	3.44		~	13622	1
8	NAME Andromeda I	G	00 45 39.8	+38 02 28		13.9	12.7		~	355	0
9	NAME Andromeda XI	G	00 46 20.0	+33 48 05			17.5		~	130	0
10	[CPI2007] J004724.69+342223.9	*	00 47 24.69	+34 22 23.9					~	3	0
11	[CPI2007] J004726.65+342322.8	*	00 47 26.65	+34 23 22.8					~	3	0
12	NAME Andromeda XII	G	00 47 27.0	+34 22 29			18.3		~	124	0
13	[CPI2007] J004727.18+342353.5	*	00 47 27.18	+34 23 53.5					~	3	0
14	[CPI2007] J004727.76+342206.2	*	00 47 27.8490	+34 22 06.320					~	3	0
15	[CPI2007] J004728.63+342243.1	*	00 47 28.63	+34 22 43.1					~	3	0
16	[CPI2007] J004730.60+342420.3	*	00 47 30.60	+34 24 20.3					~	2	0
17	[CPI2007] J004731.04+342412.1	*	00 47 31.04	+34 24 12.1					~	3	0
18	[CPI2007] J004731.34+342257.6	*	00 47 31.34	+34 22 57.6					~	3	0
19	NAME Andromeda XIV	G	00 51 35.0	+29 41 49			15.9		~	132	0
20	NAME Andromeda XIII	G	00 51 51.0	+33 00 16			18.1		~	128	0
21	NAME Andromeda IX	G	00 52 53.0	+43 11 45			16.3		~	176	1
22	NAME Pisces I	G	01 03 55.0	+21 53 06		16.18	14.3		~	404	0
23	IC 1613	GiC	01 04 48.4071	+02 07 10.185		10.42	10.01	9.77	~	1316	2
24	NAME Andromeda V	G	01 10 17.1	+47 37 41			15.3		~	215	0
25	NAME Andromeda II	G	01 16 29.8	+33 25 09			11.7		~	402	0
26	M 33	GiG	01 33 50.8965749232	+30 39 36.630403128	6.17	6.27	5.72		~	6226	1
27	M 81	Sy2	09 55 33.1726556496	+69 03 55.062505368		7.89	6.94		~	4725	3
28	Z 64-73	G	10 08 28.12	+12 18 23.4		11.3	10.0		~	1284	1
29	Z 318-18	G	15 09 08.0	+67 13 21		13.60	10.6		~	1459	0
30	Z 300-12	G	17 20 14.335	+57 55 16.39		12.40	10.6		~	1428	1
31	NAME Pisces II	G	22 58 31.0	+05 57 09			16.3		~	283	0
32	NAME Andromeda VII	GiG	23 26 31.0	+50 40 33		13.6	11.8		~	222	1
33	Z 431-72	G	23 28 35.2	+14 44 35	13.85	13.16	12.52		~	499	1
34	NAME Peg dSph	GiG	23 51 46.3	+24 34 57		14.5	13.2		~	250	2
35	NAME Local Group	GrG	~	~					~	9325	0

To bookmark this query, right click on this link: simbad:objects in 2007ApJ...662L..79C and select 'bookmark this link' or equivalent in the popup menu