The Mass Distribution in the Galactic Centre Estimated from OH/IR stars

1989 ◽  
pp. 503-508 ◽  
Author(s):  
M. Lindqvist ◽  
A. Winnberg ◽  
H. J. Habing ◽  
H. E. Matthews ◽  
F. M. Olnon
Keyword(s):  
Mass Distribution ◽  
Galactic Centre ◽  
Ir Stars

scholarly journals Dynamics of OH/IR Stars in the Inner Galactic Bulge

1993 ◽  
Vol 153 ◽  
pp. 341-342
Author(s):  
Anders Winnberg ◽  
Michael Lindqvist ◽  
Harm J. Habing
Keyword(s):  
Mass Distribution ◽  
Gravitational Potential ◽  
Progress Report ◽  
Dynamical Model ◽  
Galactic Centre ◽  
Galactic Bulge ◽  
Ir Stars

Using the VLA at 1612 MHz Lindqvist et al. (1992a) have found 134 OH/IR stars close to the Galactic Centre (GC). These stars plus 15 from Habing et al. (1983) have been used as probes of the gravitational potential to derive the mass distribution in the inner galactic bulge between ≈ 5 to ≈ 100 pc from the GC (Lindqvist et al., 1992b). In this paper we present a progress report of a dynamical model which we have applied to the data.

scholarly journals The Mass Distribution in the Galactic Centre Estimated from OH/IR Stars

1989 ◽  
Vol 136 ◽  
pp. 503-508 ◽  
Author(s):  
M. Lindqvist ◽  
A. Winnberg ◽  
H. J. Habing ◽  
H. E. Matthews ◽  
F. M. Olnon
Keyword(s):  
Density Distribution ◽  
Mass Distribution ◽  
Mass Density ◽  
Major Axis ◽  
Galactic Centre ◽  
Stellar Kinematics ◽  
Galactocentric Distance ◽  
Preliminary Results ◽  
Ir Stars ◽  
Axis Parallel

The preliminary results of a search for OH/IR stars in the Galactic Centre using the VLA are presented. The goal of this project is to determine the mass density distribution from a few parsecs up to about 120 pc of the Galactic Centre using stellar kinematics. Up to now, 125 OH/IR stars have been found. The distribution of the stars is clearly elongated with the major axis parallel to the galactic equator. The stars show a rotation of 117 km s−1 deg−1 with a dispersion of 90 km s−1. Two preliminary models have been applied in order to determine the enclosed mass, resulting in M(r)=4.0·106·r1.4 Mo, where r is the galactocentric distance in parsecs.

scholarly journals An Upper Limit to the Mass Loss from the Centre of the Galaxy

1974 ◽  
Vol 64 ◽  
pp. 36-36
Author(s):  
Arcadio Poveda ◽  
Christine Allen
Keyword(s):  
Mass Loss ◽  
Gravitational Waves ◽  
Mass Distribution ◽  
Globular Clusters ◽  
Loss Rate ◽  
Galactic Centre ◽  
Isotropic Source ◽  
The Past ◽  
Upper Limit ◽  
The Galaxy

A mass loss of 200 M⊙ per year, as conservatively suggested if Weber is detecting gravitational waves from an isotropic source at the galactic centre, is shown to be incompatible with the existence of (a) globular clusters, (b) old wide binaries, if this loss rate has been constant over the past 1010 yr.From the orbit of ω Centauri in the galactic field and its observed mass distribution and tidal radius an upper limit to the mass loss from the galactic centre is found to be 1 M⊙ yr-1 over the past 1010 yr.

OH/IR stars and the Galactic Centre distance

1993 ◽  
pp. 345-348 ◽  
Author(s):  
Jessica M. Chapman ◽  
N. E. B. Killeen ◽  
P. te Lintel Hekkert ◽  
J. L. Caswell ◽  
J. Harnett
Keyword(s):  
Galactic Centre ◽  
Ir Stars

scholarly journals A Southern Survey of OH Masers at 1612 MHz

1981 ◽  
Vol 34 (3) ◽  
pp. 333 ◽  
Author(s):  
JL Caswell ◽  
RF Haynes ◽  
WM Goss ◽  
U Mebold
Keyword(s):  
Galactic Plane ◽  
Galactic Centre ◽  
Emission Sources ◽  
Classification Schemes ◽  
Mira Variables ◽  
Population Type ◽  
Ir Stars ◽  
Kinematic Properties ◽  
Line Type

A search for OH at 1612 MHz has been made along the galactic plane from longitude 3400 to the galactic centre, yielding 78 emission sources (mostly new discoveries); a further 5 sources have been found in a less sensitive survey between longitudes 2700 and 3260 Of these 83 sources 55 are masers of the variety showing two intensity peaks spaced in velocity-a characteristic of OH/IR stars. The velocity and spatial distributions of these new OHjIR stars (which are not as yet identified in the optical or infrared) are discussed, with special reference to their kinematic properties and population type; it is still not clear whether they are predominantly late-type giants (Mira variables) or supergiants. The other 28 OH sources detected include 11 of the type lIe variety (extended OH clouds exhibiting 1612 MHz emission with accompanying 1720 MHz absorption) and 4 with accompanying main-line (type 1)OH masers; the remaining 13 sources do not readily fit within existing classification schemes and are discussed individually

scholarly journals Possible Evidence for a Binary Massive Black Hole in the Galactic Nucleus

1996 ◽  
Vol 169 ◽  
pp. 285-286
Author(s):  
E.J.A. Meurs
Keyword(s):  
Black Hole ◽  
Emission Line ◽  
Velocity Component ◽  
Orbital Motion ◽  
Galactic Centre ◽  
Line Profiles ◽  
Radial Velocity Component ◽  
Massive Black Hole ◽  
Ir Stars ◽  
Sgr A

The Galactic Centre candidate Sgr A∗ may exhibit a 40 km/s radial velocity component, which is not observed for OH/IR stars around the centre. This could be interpreted as orbital motion of one member of a binary massive black hole. In other galaxies such pairs may be inferred from radio jet precession and emission line profiles.

OH/IR Stars Near the Galactic Centre

1983 ◽  
pp. 542-543 ◽  
Author(s):  
H. J. Habing ◽  
F. M. Olnon ◽  
A. Winnberg ◽  
H. E. Matthews ◽  
B. Baud
Keyword(s):  
Galactic Centre ◽  
Ir Stars

scholarly journals 86-GHz SiO masers in Galactic centre OH/IR stars

2020 ◽  
Vol 72 (4) ◽  
Author(s):  
Maria Messineo ◽  
Lorant O Sjouwerman ◽  
Harm J Habing ◽  
Alain Omont
Keyword(s):  
Detection Rate ◽  
Space Experiment ◽  
Galactic Centre ◽  
Maser Emission ◽  
Circumstellar Material ◽  
Spectral Peaks ◽  
Ir Stars ◽  
Molecular Transition

Abstract We present results on a search for 86.243-GHz SiO (J = 2→1, $v$ = 1) maser emission toward 67 OH/IR stars located near the Galactic centre. We detected 32 spectral peaks, of which 28 correspond to SiO maser lines arising from the envelopes of these OH/IR stars. In OH/IR stars, we obtained an SiO maser detection rate of about $40\%$. We serendipitously detected two other lines from OH/IR stars at ≈86.18 GHz, which could be due to a CCS-molecule transition at 86.181 GHz or probably to an highly excited OH molecular transition at 86.178 GHz. The detection rate of 86-GHz maser emission is found to be about $60\%$ for sources with the Midcourse Space Experiment (MSX) A − E < 2.5 mag; but it drops to $25\%$ for the reddest OH/IR stars with MSX A − E > 2.5 mag. This supports the hypothesis by Messineo (2002, A&A, 393, 115) that the SiO masers are primarily found in relatively thinner circumstellar material.

scholarly journals OH/IR Stars Near the Galactic Centre

1983 ◽  
Vol 103 ◽  
pp. 542-543
Author(s):  
H.J. Habing ◽  
F.M. Olnon ◽  
A. Winnberg ◽  
H.E. Matthews ◽  
B. Baud
Keyword(s):  
Spatial Distribution ◽  
High Velocity ◽  
Surface Brightness ◽  
Velocity Dispersion ◽  
Galactic Centre ◽  
Galactic Rotation ◽  
Red Giants ◽  
Large Array ◽  
Very Large Array ◽  
Ir Stars

We have detected 34 OH/IR stars within 1 degree of the galactic centre by their OH emission line at 1612 MHz (18 cm) using the Effelsberg 100 m telescope and the Very Large Array. The spatial distribution and the distribution of the radial velocities show that practically all stars are within 150 pc from the Galactic centre, and that the number of foreground objects is very small. The projected distribution of the stars is similar to that of the surface brightness at 2.4 μm. Since the 2.4 μm radiation is supposed to be due to red giants, the OH/IR stars are probably members of the same population. The stars have considerable random velocities (velocity dispersion in one coordinate of 150 ± 50 km s−1), but show general Galactic rotation. The high velocity dispersion is remarkable for objects of this population.

Mass distribution in the galactic centre

Nature ◽  
1985 ◽  
Vol 315 (6019) ◽  
pp. 467-470 ◽  
Author(s):  
M. K. Crawford ◽  
R. Genzel ◽  
A. I. Harris ◽  
D. T. Jaffe ◽  
J. H. Lacy ◽  
...  
Keyword(s):  
Mass Distribution ◽  
Galactic Centre
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