Infrared Scanning of the Galactic Bulge

Catchpole, R. M.; Whitelock, Patricia; Glass, Ian S.

doi:10.1007/978-94-009-5291-1_16

Cited by 58 publications

(80 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Above this limit, the comparison is affected by increased internal errors in both extinction determinations. However, a comparison with the Galactic center map of Catchpole et al (1990) gives a good agreement with differences less than A V = 2 mag. The resulting map has a spatial resolution of 2 arcminutes and is the average total extinction along that line of sight to a distance of 8 kpc from the Sun.…”

Section: Extinction In the Galactic Central Regionsmentioning

confidence: 58%

The visibility of the Galactic bulge in optical surveys. Application to the Gaia mission

Robin

Reylé

Picaud

et al. 2005

A&A

View full text Add to dashboard Cite

Abstract. The bulge is a region of the Galaxy which is of tremendous interest for understanding Galaxy formation. However, measuring photometry and kinematics in it raises several inherent issues, like high extinction in the visible and severe crowding. Here we attempt to estimate the problem of the visibility of the bulge at optical wavelengths, where large CCD mosaics allow to easily cover wide regions from the ground, and where future astrometric missions are planned. Assuming the Besançon Galaxy model and high resolution extinction maps, we estimate the stellar density as a function of longitude, latitude and apparent magnitude and we deduce the possibility of reaching and measuring bulge stars. The method is applied to three Gaia instruments, the BBP and MBP photometers, and the RVS spectrograph. We conclude that, while in the BBP most of the bulge will be accessible, in the MBP there will be a small but significant number of regions where bulge stars will be detected and accurately measured in crowded fields. Assuming that the RVS spectra may be extracted in moderately crowded fields, the bulge will be accessible in most regions apart from the strongly absorbed inner plane regions, because of high extinction, and in low extinction windows like the Baades's window where the crowding is too severe.

show abstract

Section: Extinction In the Galactic Central Regionsmentioning

confidence: 58%

The visibility of the Galactic bulge in optical surveys. Application to the Gaia mission

Robin

Reylé

Picaud

et al. 2005

A&A

View full text Add to dashboard Cite

show abstract

“…The enclosed mass in the region 5 [ r/pc [ 100 obtained by Lindqvist et al (1992a) also implies a surface density proÐle of P r~0.8. On the other hand, by Ðtting an ellipse with an aspect ratio of 2.2 to the distribution of stars with dereddened, apparent K mag between 5 and 6 (Haller & Rieke 1999 estimate such stars to be a few 108 yr old), Catchpole et al (1990) obtained by Catchpole et al In any case, it appears reasonable to assume that the time-averaged star formation efficiency in the inner bulge has a dependence between R~2 and R~1 in the plane.…”

Section: Density Proðles and Aspect Ratiosmentioning

confidence: 95%

“…While the aspect ratio of the bulge is 1.6È1.7 (Kent, Dame, & Fazio 1991 ;Weiland et al 1994), those of the stellar population and the CMZ are D2.2 (Catchpole, Whitelock, & Glass 1990) and D4 , respectively. The mass of the stellar population within the D100 pc extent of the CMZ, D109 falls near the lower end of the range M _ , predicted for the stellar mass emerging from the CMZ over the GalaxyÏs lifetime, and consider this to be additional support for the association between the stellar population and the CMZ.…”

Section: Introductionmentioning

confidence: 99%

Spatial Diffusion of Stars in the Inner Galactic Bulge

Kim

Morris

2001

ApJ

View full text Add to dashboard Cite

Star formation in the inner few hundred parsecs of the Galactic bulge occurs in a Ñattened molecular layer called the central molecular zone (CMZ). It has been suggested that star formation in the CMZ has been sustained for the lifetime of the Galaxy and that the resulting agglomeration of stars formed in the CMZ has resulted in the prominent r~2 stellar density cusp at the Galactic center having about the same physical extent as the CMZ. This "" central cusp ÏÏ is somewhat less Ñat than the CMZ ; thus, the population of stars formed in the CMZ appears to have di †used out to larger latitudes. We hypothesize that such vertical di †usion is driven by the scattering of stars o † the giant molecular clouds (GMCs) in the CMZ and perform numerical simulations of the scattering between stars and GMCs in the presence of the nonaxisymmetric background potential. The simulation results show that the timescale for an initially Ñattened stellar population to achieve an aspect ratio of the observed OH/IR stars in the inner bulge, 1È2 Gyr, agrees well with the estimated age of those OH/IR stars.

show abstract

“…Any bar-like structure will be centrally concentrated, and a relatively small survey concentrating on sources near the centre will have enough statistical weight to show up longitude dependent asymmetries, if they exist. The only moderately sized, multicolour, higher resolution survey, covering about 2 • × 0.5 • around the Galactic centre, is by Catchpole, Whitelock and Glass (1990). It was performed in the J, H and K bands up to a limiting magnitude of K=12.…”

Section: Introductionmentioning

confidence: 99%

Near-infrared star counts as a test of a Galactic bar structure

Unavane¹

1998

MNRAS

View full text Add to dashboard Cite

We present survey data in the narrow-band L filter (nbL), taken at UKIRT, for a total area of 277 arcmin 2 , roughly equally divided between four regions at zero Galactic latitude and longitudes ±4.3 • and ±2.3 • . The 80 per cent completeness level for these observations is at roughly magnitude 11.0. This magnitude limit, owing to the low coefficient for interstellar extinction at this wavelength (A nbL =0.047A V ), allows us to observe bulge giants. We match the nbL-magnitudes with DENIS survey K magnitudes, and find 95 per cent of nbL sources are matched to K sources. Constructing colour-magnitude diagrams, we deredden the magnitudes and find evidence for a longitude dependent asymmetry in the source counts. We find that there are ∼15 per cent and ∼5 per cent more sources at the negative longitude than at the corresponding positive longitude, for the fields at ±4.3 • and ±2.3 • respectively. This is compared with the predictions of some Galactic bar models. We find an asymmetry in the expected sense, which favours gas dynamical models and the recent deconvolution of surface photometry data (Binney et al. 1991;Binney, Gerhard & Spergel 1997), over earlier treatments of photometric data (e.g. Dwek et al. 1995).

show abstract

Infrared Scanning of the Galactic Bulge

Cited by 58 publications

References 3 publications

The visibility of the Galactic bulge in optical surveys. Application to the Gaia mission

The visibility of the Galactic bulge in optical surveys. Application to the Gaia mission

Spatial Diffusion of Stars in the Inner Galactic Bulge

Near-infrared star counts as a test of a Galactic bar structure

Contact Info

Product

Resources

About