J/ApJ/822/49 Candidate YSOs in AFGL 333 with NEWFIRM & Spitzer (Jose+, 2016)
Star formation in W3-AFGL 333: young stellar content, properties, and
roles of external feedback.
Jose J., Kim J.S., Herczeg G.J., Samal M.R., Bieging J.H., Meyer M.R.,
Sherry W.H.
<Astrophys. J., 822, 49-49 (2016)>
=2016ApJ...822...49J 2016ApJ...822...49J (SIMBAD/NED BibCode)
ADC_Keywords: YSOs ; Photometry, infrared ; Molecular clouds
Keywords: stars: formation; stars: pre-main sequence
Abstract:
One of the key questions in the field of star formation is the role of
stellar feedback on the subsequent star formation process. The W3
giant molecular cloud complex at the western border of the W4 super
bubble is thought to be influenced by the massive stars in W4. This
paper presents a study of the star formation activity within AFGL 333,
a ∼104M☉ cloud within W3, using deep JHKs photometry obtained
from the NOAO Extremely Wide Field Infrared Imager combined with
Spitzer IRAC and MIPS photometry. Based on the infrared excess, we
identify 812 candidate young stellar objects (YSOs) in the complex, of
which 99 are Class I and 713 are Class II sources. The stellar density
analysis of YSOs reveals three major stellar aggregates within
AFGL333, namely AFGL 333 Main, AFGL 333 NW1 and AFGL 333 NW2. The disk
fraction within AFGL 333 is estimated to be ∼50%-60%. We use the
extinction map made from the H-Ks colors of the background stars and
CO data to understand the cloud structure and to estimate the cloud
mass. From the stellar and cloud mass associated with AFGL 333, we
infer that the region is currently forming stars with an efficiency of
∼4.5% and at a rate of ∼2-3M☉/Myr/pc2. In general, the star
formation activity within AFGL 333 is comparable to that of nearby low
mass star-forming regions. We do not find any strong evidence to
suggest that the stellar feedback from the massive stars of nearby W4
super bubble has affected the global star formation properties of the
AFGL 333 region.
Description:
We obtained NIR observations of AFGL 333 in JHKs bands using the
National Optical Astronomical Observatory (NOAO) Extremely Wide Field
InfraRed Imager (NEWFIRM) camera on the 4m Mayal telescope at Kitt
Peak National Observatory (KPNO) on 2009 December 6.
Images from the Spitzer Space Telescope using the Infrared Array
Camera (IRAC) centered at 3.6, 4.5, 5.8, and 8.0um (ch1, ch2, ch3, and
ch4) were obtained from the Spitzer archive. These observations were
taken on 2004 January 10 and 2007 February 19 (Program IDs: 30955,
127; PIs: R. Gehrz, T. Moore). Preliminary analyses of these data sets
have been presented in Ruch et al. (2007, J/ApJ/654/338) and
Rivera-Ingraham et al. (2011, J/ApJ/743/39).
AFGL 333 was observed in 24um using the Multi-band Imaging Photometer
for Spitzer (MIPS) on 2004 February 03 (Program ID: 127, PI: R. Gehrz).
Objects:
----------------------------------------------------------
RA (ICRS) DE Designation(s)
----------------------------------------------------------
02 27 04.10 +61 52 27.1 W3 = GRS G133.70 +01.20
02 32 42 +61 27.0 AFGL 333 = IC 1805
----------------------------------------------------------
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 83 9720 Photometric data of all point sources within AFGL333
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See also:
II/326 : Revised SWIRE photometric redshifts (Rowan-Robinson+, 2013)
J/A+A/585/A49 : VCNS II. The IR-excess-selected population (Zeidler+, 2016)
J/ApJ/813/42 : O and B type stars in W3: first results (Kiminki+, 2015)
J/A+A/561/A12 : W3 Main JHKs photometry (Bik+, 2014)
J/A+A/554/A3 : Vilnius photometry of IC1805 stars (Straizys+, 2013)
J/ApJS/209/31 : The MYStIX IR-Excess Source catalog (MIRES) (Povich+, 2013)
J/ApJ/778/96 : Spitzer and NEWFIRM observations of NGC 6334 (Willis+, 2013)
J/ApJ/743/39 : Spitzer obs. of W3 molecular cloud (Rivera-Ingraham+, 2011)
J/ApJS/196/18 : CO survey of galactic molecular clouds. II. (Bieging+, 2011)
J/ApJ/726/19 : Intermediate-mass stars in IC 1805 (Wolff+, 2011)
J/ApJ/723/1019 : Galactic SFR and gas surface densities (Heiderman+, 2010)
J/ApJS/184/18 : Spitzer survey of young stellar clusters (Gutermuth+, 2009)
J/ApJS/181/321 : Properties of Spitzer c2d dark clouds (Evans+, 2009)
J/ApJ/688/1142 : Star formation in W5: Spitzer observations (Koenig+, 2008)
J/AJ/136/2413 : Galactic midplane Spitzer red sources (Robitaille+, 2008)
J/A+A/487/993 : MAMBO Mapping of c2d Clouds and Cores (Kauffmann+, 2008)
J/MNRAS/379/663 : 850um observations of W3 giant molecular cloud (Moore+, 2007)
J/ApJ/654/338 : Spitzer photometry in W3 molecular cloud (Ruch+, 2007)
J/ApJ/651/502 : Spitzer IRAC photometry of M, L, and T dwarfs (Patten+, 2006)
J/AJ/132/663 : Differential Velocities of very low mass SBs (Basri+, 2006)
J/AJ/129/393 : UBV photometry in W3 (Oey+, 2005)
J/A+A/397/177 : IR star clusters and stellar groups catalog (Bica+, 2003)
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 7 F7.4 deg RAdeg Right Ascension in decimal degrees (J2000)
9- 16 F8.4 deg DEdeg Declination in decimal degrees (J2000)
18- 22 F5.2 mag Jmag [6.1/21.5]? The NOAO/NEWFIRM J band magnitude
24- 28 F5.2 mag Hmag [5.3/20]? The NOAO/NEWFIRM H band magnitude
30- 34 F5.2 mag Ksmag [5.1/18]? The NOAO/NEWFIRM Ks band magnitude
36- 40 F5.2 mag 3.6mag [3.7/17.6]? Spitzer/IRAC 3.6um band magnitude
42- 46 F5.2 mag 4.5mag [3.9/17.1]? Spitzer/IRAC 4.5um band magnitude
48- 52 F5.2 mag 5.8mag [3.6/14.8]? Spitzer/IRAC 5.8um band magnitude
54- 58 F5.2 mag 8.0mag [4.6/14]? Spitzer/IRAC 8.0um band magnitude
60- 63 F4.2 mag 24mag [1/9.4]? Spitzer/MIPS 24um band magnitude
65- 69 A5 --- --- [class]
70- 83 A14 --- Class Classification (99 sources "I", 713 class "II",
and 8908 "III/field star")
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 02-Aug-2016