J/other/ApSS/344.175 Protoclusters and subclusters (Majaess, 2013)
Discovering protostars and their host clusters via WISE.
Majaess D.
<Astrophys. Space Sci. 344, 175 (2013)>
=2013Ap&SS.344..175M 2013Ap&SS.344..175M
ADC_Keywords: YSOs ; Infrared sources ; Clusters, open
Keywords: circumstellar matter - infrared: stars - stars: formation
Abstract:
A hybrid JHKs - W1W2W3W4 high-spectral index (α) selection scheme
was employed to identify (sub)clusters of class I/f candidate
protostars (YSOs) in WISE observations (the Wide-Field Infrared Survey
Explorer). n>104 candidate YSOs were detected owing to WISE's
advantageous all-sky spatial coverage, and a subsample (n∼200) of
their heavily-obscured host (sub)clusters were correlated with the
Avedisova (2002, Cat. V/112) and Dias et al. (2002A&A...389..871D 2002A&A...389..871D,
Cat. B/ocl) catalogs of star-forming regions. Forthcoming observations
from the VVV/UKIDSS surveys shall facilitate the detection of
additional protostars and bolster efforts to delineate the Galactic
plane, since the campaigns aim to secure deep JHKs photometry for a
pertinent fraction of the WISE targets lacking 2MASS detections, and
to provide improved data for YSOs near the limits of the 2MASS survey.
Description:
This file contains a subsample of the embedded clusters identified,
with an emphasis on smaller overlooked subclusters, whereby
subclusters are offshoot clumps of emerging stars tied to broader
star-forming regions (hierarchical clustering). The bulk of the
targets deviate from spherical symmetry and are typically associated
with larger complexes. Apparent sizes for the (sub)clusters are
tabulated, and those entries tagged by an asterisk contain few
members. The majority of the targets will dissolve prior to becoming
an intermediate-age cluster. Clusters which were serendipitously
identified as a result of the analysis are likewise tabulated.
Numerous objects are not discernible in optical and even W1 images,
which underscores the extreme obscuration endemic to the host
environment. Following discussions with Dias et al., the cluster of
class I/f YSOs discovered near the classical Cepheid SU Cas (Majaess
et al. 2012MNRAS.421.1040M 2012MNRAS.421.1040M) is included as Majaess 230. New WISE
mid-IR data unambiguously revealed a cluster of numerous class I/f
YSOs centred at J2000 02:54:31.4 +69:20:32.5, and a nearby YSO and
2MASS overdensity were noted previously (e.g. Straizys & Kazlauskas
2010BaltA..19....1S 2010BaltA..19....1S, Froebrich et al. 2007MNRAS.374..399F 2007MNRAS.374..399F). In sum,
the results reaffirm the importance of the latest generation of
infrared surveys (e.g., WISE) for enabling the detection of YSOs and
their nascent environments. However, significant work remains and
subsequent refinement to the YSO selection scheme pending the
identification of biases is inevitable. Spectroscopic, deep IR
photometric, and sub-mm (ALMA) follow-up observations for the cluster
targets are desirable, and forthcoming.
This publication makes use of data products from WISE, 2MASS, CDS,
arXiv, NASA/IPAC ISA, and NASA ADS.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 78 230 YSO complexes and (sub)clusters
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See also:
II/311 : WISE All-Sky Data Release (Cutri+ 2012)
B/ocl : Optically visible open clusters and Candidates (Dias+ 2002-2012)
V/112 : Catalog of Star-Forming Regions in the Galaxy (Avedisova, 2002)
J/BaltA/19/1 : YSOs in Camelopardalis (Straizys+, 2010)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 7 A7 --- --- [Majaess]
9- 11 I3 --- ID [1/230] Target number (ID is <Majaess NNN>)
15- 16 I2 h RAh Right ascension (J2000)
18- 19 I2 min RAm Right ascension (J2000)
21- 25 F5.2 s RAs Right ascension (J2000)
27 A1 --- DE- Declination sign (J2000)
28- 29 I2 deg DEd Declination (J2000)
31- 32 I2 arcmin DEm Declination (J2000)
34- 37 F4.1 arcsec DEs Declination (J2000)
39- 40 I2 arcmin Diam Apparent diameter
42 A1 --- Note [*] indicates that the target contains
a few members.
45- 56 A12 --- A02 Closest cluster in Avedisova 2002, Cat. V/112
58- 59 I2 arcmin rA [1/30]? Offset of target from A02 (1)
62- 74 A13 --- D02 Closest cluster from Dias et al. 2002
(see Cat. B/ocl)
77- 78 I2 arcmin rD [1/20]? Offset of target from D02 (1)
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Note (1): values marked "1" mean a distance ≤1arcmin.
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Acknowledgements:
Dan Majaess, dmajaess(at)ns.sympatico.ca
(End) Dan Majaess [Halifax, Canada], Francois Ochsenbein [CDS] 28-Dec-2012