Bolocam GPS Distance Catalog Definitions


The Bolocam Galactic Plane Survey (BGPS) is a 1.1 mm continuum survey of the Galactic Plane made using Bolocam on the Caltech Submillimeter Observatory. Millimeter-wavelength thermal dust emission reveals the repositories of the densest molecular gas, ranging in scale from cores to whole clouds. By pinpointing these regions, the connection of this gas to nascent and ongoing star formation may be explored. The BGPS coverage totals 170 square degrees (with 33" FWHM effective resolution). The survey is contiguous over the range -10.5 ≤ l ≤ 90.5, |b| ≤ 0.5. Towards the Cygnus X spiral arm, the coverage was flared to |b| ≤ 1.5 for 75.5 ≤ l ≤ 87.5. In addition, cross-cuts to |b| ≤ 1.5 were made at l = 3, 15, 30 and 31. The total area of this section is 133 square degrees. With the exception of the increase in latitude, no pre-selection criteria were applied to the coverage in this region. In addition to the contiguous region, four targeted regions in the outer Galaxy were observed: IC1396 (9 square degrees, 97.5 ≤ l ≤ 100.5, 2.25 ≤ l ≤ 5.25), a region towards the Perseus Arm (4 square degrees centered on l = 111, b=0 near NGC7538), W3/4/5 (18 square degrees, 132.5 ≤ l ≤ 138.5) and Gem OB1 (6 square degrees, 187.5 ≤ l ≤ 193.5). The survey has detected approximately 8,400 sources, to an rms noise level in the maps ranging from 30 to 60 mJy beam-1. The BGPS survey and catalog provide an important database for sub/millimeter observations with the Herschel Space Observatory, ALMA, SCUBA-2, APEX, and others.

The Distance Catalog is described in Ellsworth-Bowers et al. (2013) and Ellsworth-Bowers et al. (2015). The Distance Catalog contains 3508 sources.

Name Intype Units Description
num int Bolocam v2.1 Catalog Number
glon double deg Galactic longitude
glat double deg Galactic latitude
flux double Jy Integrated BGPS Flux Density
eflux double Jy Standard error on flux
vlsr double km/s LSR velocity
rv char reference for vlsr:
1 = Shirley et al. (2013)
2 = Shirley (2012, private communication)
3 = Dunham et al. (2011b)
4 = Dunham et al. (2010)
5 = Lichtenberger (2014, private communication)
6 = Ellsworth-Bowers et al. (2015)
kdr char KDA resolution:
N = near
F = far
T = tangent
O = outer Galaxy
U = unconstrained
pml double Maximum-likelihood probability:
The integrated posterior DPDF on the d_ML side of the tangent point; used as a proxy for the quality of the distance constraint.
dml double kpc Maximum-likelihood distance
ledml double kpc Lower error in dml
uedml double kpc Upper error in dml
dbar double kpc Weighted-average distance
edbar double kpc Error in dbar
rgal double kpc Galactocentric radius
Rgal is unambiguous and is computed from VLSR and assumed uncertainty of 7 km/s (Reid et al. 2009b) for sources without a well-constrained distance estimate.
lrgl double kpc Lower error on rgal
urgl double kpc Upper error on rgal
z_gal double kpc Galactocentric vertical position
e_z double kpc Error in z_gal
Errors include contributions from variations in z along the line of sight over the range d {+/-} {sigma}_d_ and the {+/-} 5 km/s uncertainty in the solar offset above the Galactic midplane (Juric et al. 2008), added in quadrature.
ra double deg Right Ascension (J2000)
dec double deg Declination (J2000)