J/ApJ/681/428 BLAST sources in Galactic plane survey (Chapin+, 2008)
The balloon-borne large aperture submillimeter telescope (BLAST) 2005:
a 4 deg2 galactic plane survey in Vulpecula (l = 59°).
Chapin E.L., Ade P.A.R., Bock J.J., Brunt C., Devlin M.J., Dicker S.,
Griffin M., Gundersen J.O., Halpern M., Hargrave P.C., Hughes D.H.,
Klein J., Marsden G., Martin P.G., Mauskopf P., Netterfield C.B., Olmi L.,
Pascale E., Patanchon G., Rex M., Scott D., Semisch C., Truch M.D.P.,
Tucker C., Tucker G.S., Viero M.P., Wiebe D.V.
<Astrophys. J., 681, 428-452 (2008)>
=2008ApJ...681..428C 2008ApJ...681..428C
ADC_Keywords: Millimetric/submm sources ; Interstellar medium ; Infrared sources
Keywords: balloons - ISM: clouds - stars: formation - submillimeter
Abstract:
We present the first results from a new 250, 350, and 500um Galactic
plane survey taken with the Balloon-borne Large-Aperture Submillimeter
Telescope (BLAST) in 2005. This survey's primary goal is to identify
and characterize high-mass protostellar objects (HMPOs). The region
studied here covers 4°2 near the open cluster NGC 6823 in the
constellation Vulpecula (l=59°). We find 60 compact sources (<60"
diameter) detected simultaneously in all three bands. Their SEDs are
constrained through BLAST, IRAS, Spitzer MIPS, and MSX photometry,
with inferred dust temperatures spanning ∼12-40K assuming a dust
emissivity index β=1.5. The luminosity-to-mass ratio, a
distance-independ ent quantity, spans ∼0.2-130L☉/M☉.
Distances are estimated from coincident 13CO(1-0) velocities
combined with a variety of other velocity and morphological data in
the literature. In total, 49 sources are associated with a molecular
cloud complex encompassing NGC 6823 (distance ∼2.3kpc), 10 objects
with the Perseus arm (∼8.5kpc), and one object is probably in the
outer Galaxy (∼14kpc). Near NGC 6823, the inferred luminosities and
masses of BLAST sources span ∼40-104L☉ and ∼15-700M☉,
respectively. The mass spectrum is compatible with molecular gas
masses in other high-mass star-forming regions. Several luminous
sources appear to be ultracompact H II regions powered by early B
stars. However, many of the objects are cool, massive gravitationally
bound clumps with no obvious internal radiation from a protostar, and
hence excellent HMPO candidates.
Description:
Flux densities for BLAST sources are quoted at precisely 250, 350,
and 500 micron using SED fits to obtain color-corrections for the
band-averaged flux densities. The quoted statistical uncertainties
are determined from Monte Carlo simulations, and do not include
calibration uncertainties.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 65 60 Fluxes and positions of BLAST sources
table3.dat 55 23 IRAS PSC counterparts
table4.dat 49 60 IRAS and Spitzer MIPS photometry
table5.dat 35 51 MSX counterparts
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 3 A3 --- [CAB2008] Internal paper designation (VNN)
4- 5 A2 --- n_[CAB2008] [abc ] Note on [CAB2008] (1)
7- 11 A5 --- --- [BLAST]
13- 26 A14 --- BLAST Official BLAST Designation, JHHMMSS+DDMMSS
28- 33 F6.1 Jy F250 Flux at 250 microns (1200GHz)
35- 38 F4.1 Jy e_F250 Error at 250 microns
40- 44 F5.1 Jy F350 Flux at 350 microns (850GHz)
46- 48 F3.1 Jy e_F350 Error at 350 microns
50- 54 F5.1 Jy F500 Flux at 500 microns (600GHz)
56- 58 F3.1 Jy e_F500 Error at 500 microns
60- 64 F5.1 km/s Vlsr Line of sight velocity from CO
65 A1 --- f_Vlsr [de] another Vlsr component exists (1)
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Note (1): Notes as follows:
a = These sources are located on ripples in the deconvolved map and
the BLAST colors are considered unreliable as a result
b = V07 is believed to lie in the outer galaxy
c = These sources are associated with a molecular cloud in the Perseus arm
d = Also has a comparable component at -15km/s
e = Also has a comparable component at 23km/s
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 3 A3 --- [CAB2008] BLAST Variable name, VNN
4 A1 --- n_[CAB2008] [cd] Note on [CAB2008] (1)
6- 15 A10 --- IRAS IRAS designation (HHMMm+DDMM) (2)
17- 21 F5.1 arcsec DRA Difference in right ascension (3)
23- 27 F5.1 arcsec DDE Difference in declination (3)
29- 32 F4.1 Jy F12 IRAS flux as 12um
33 A1 --- q_F12 [b] upper limit (4)
35- 39 F5.1 Jy F25 IRAS flux at 25um
40 A1 --- q_F25 [b] upper limit (4)
42- 46 F5.1 Jy F60 IRAS flux at 60um
47 A1 --- q_F60 [b] upper limit (4)
49- 54 F6.1 Jy F100 IRAS flux at 100um
55 A1 --- q_F100 [b] upper limit (4)
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Note (1): Notes as follows:
c = IRAS 19404+2342 is close to both V19 and V23; the ambiguity is
resolved with the improved resolution of the MIPS 70um map
d = Although IRAS 19413+2349 and IRAS 19416+2312 are close to V38 and
V53, respectively, their SEDs are not compatible with the BLAST
photometry and the identifications are not used in subsequent analyses
Note (2): IRAS point sources associated with BLAST objects. The search
radius is a variable function of both BLAST and IRAS positional
uncertainties (see Sect. 3.1).
Note (3): BLAST source tangent plane offsets (east and north) compared to
IRAS source position.
Note (4): 'b' indicates IRAS measurements flagged as upper limits in the
catalog (usually due to confusion). Values from Table 4 are used instead.
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 3 A3 --- [CAB2008] BLAST Variable name, VNN
6- 9 F4.1 Jy F12 IRAS flux as 12um
10 A1 --- n_F12 [a] good IRAS PSC detection (1)
12 A1 --- q_F12 [gnu] quality flag, g=good (2)
14- 18 F5.1 Jy F25 IRAS flux at 25um
19 A1 --- n_F25 [a] good IRAS PSC detection (1)
21 A1 --- q_F25 [gnu] quality flag, g=good (2)
23- 27 F5.1 Jy F60 IRAS flux at 60um
28 A1 --- n_F60 [a] good IRAS PSC detection (1)
30 A1 --- q_F60 [gnu] quality flag, g=good (2)
32- 37 F6.1 Jy F100 IRAS flux at 100um
38 A1 --- n_F100 [a] good IRAS PSC detection (1)
40 A1 --- q_F100 [gnu] quality flag, g=good (2)
43- 47 F5.1 Jy F70 MIPA flux at 70um
49 A1 --- q_F70 [gnus] quality flag, g=good (2)
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Note (1): 'a' indicates that clear detections from the IRAS PSC (Table 3)
are used in favor of these values when available.
Note (2): Each measurement is flagged on visual inspection as follows:
g = if it is good
u = for upper limit
n = for no visible source
s = for saturated (unreliable) values in the MIPS 70um map.
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Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
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1- 3 A3 --- [CAB2008] BLAST Variable name, VNN
5- 9 F5.1 arcsec DRA Offset in right ascension with MSX source (1)
11- 15 F5.1 arcsec DDE Offset in declination with MSX source (1)
18- 20 F3.1 Jy F8.3 MSX flux as 8.3um
23- 25 F3.1 Jy F12.1 ?=- MSX flux at 12.1um
27- 30 F4.1 Jy F14.7 ?=- MSX flux at 14.7um
32- 35 F4.1 Jy F21.3 ?=- MSX flux at 21.3um
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Note (1): BLAST source tangent plane offsets (east and north) compared to
MSX source position.
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Acknowledgements:
Matthew Truch, matthew(at)truch.net,
Marie Rex, madamson(at)physics.upenn.edu
(End) Matthew Truch [UPenn, USA], Patricia Vannier [CDS] 15-May-2009