J/ApJ/891/81 Deep optical and infrared photometry of Sh2-305 (Pandey+, 2020)
Stellar cores in the Sh 2-305 HII region.
Pandey R., Sharma S., Panwar N., Dewangan L.K., Ojha D.K., Bisen D.P.,
Sinha T., Ghosh A., Pandey A.K.
<Astrophys. J., 891, 81 (2020)>
=2020ApJ...891...81P 2020ApJ...891...81P
ADC_Keywords: H II regions; YSOs; Photometry, infrared; Photometry, UBVRI;
Proper motions; Stars, ages; Stars, masses; Extinction;
Interstellar medium
Keywords: Interstellar medium ; H II regions ; Open star clusters ;
Star formation ; Star forming regions
Abstract:
Using our deep optical and near-infrared photometry along with
multiwavelength archival data, we here present a detailed study of the
Galactic HII region Sh 2-305 to understand the star/star-cluster
formation. On the basis of excess infrared emission, we have
identified 116 young stellar objects (YSOs) within a field of view of
∼18.5'x18.5' around Sh 2-305. The average age, mass, and extinction
(AV) for this sample of YSOs are 1.8Myr, 2.9M☉, and 7.1mag,
respectively. The density distribution of stellar sources along with
minimal spanning tree calculations on the location of YSOs reveals at
least three stellar subclusterings in Sh 2-305. One cluster is seen
toward the center (i.e., Mayer 3), while the other two are distributed
toward the north and south directions. Two massive O-type stars (VM2
and VM4; ages ∼5Myr) are located at the center of the Sh 2-305 HII
region. The analysis of the infrared and radio maps traces the
photon-dominant regions (PDRs) in Sh 2-305. The association of the
younger generation of stars with the PDRs is also investigated in
Sh2-305. This result suggests that these two massive stars might have
influenced the star formation history in Sh 2-305. This argument is
also supported by the calculation of various pressures driven by
massive stars, the slope of the mass function/K-band luminosity
function, star formation efficiency, fraction of Class I sources, and
mass of the dense gas toward the subclusterings in Sh 2-305.
Description:
The broadband UBV(RI)c optical observations of Sh 2-305 were taken
using a 2Kx2K CCD camera mounted on the f/4 Cassegrain focus of the
1.3m Devasthal fast optical telescope (DFOT) of the Aryabhatta
Research Institute of Observational Sciences (ARIES), Nainital, India.
See Section 2.1.
NIR imaging data in JHK bands were taken using the TIFR Near Infrared
Spectrometer and Imager (TIRSPEC) mounted on the 2m Himalayan Chandra
Telescope (HCT), Hanle, Ladakh, India. See Section 2.2.
Sh 2-305 was observed by the Spitzer space telescope on 2011 August 9
(program ID:61071; PI: Whitney Barbara A) with the Infrared Array
Camera (IRAC) at 3.6um and 4.5um. We obtained the basic calibrated
data (BCD) of the region from the Spitzer data archive. See Section 2.3.
We have also used the 2MASS NIR (JHKs) point source catalog (PSC; II/246)
for Sh 2-305. This catalog is reported to be 99% complete down to the
limiting magnitudes of 15.8, 15.1, and 14.3 in the J, H, and Ks bands,
respectively. We have selected only those sources which have NIR
photometric accuracy <0.2mag and detection in at least the H and Ks bands.
We make also use of the AllWISE catalog (II/328) of the WISE survey data.
See Section 2.5.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 81 137 Stars identified as members of Sh 2-305
table4.dat 153 116 IR photometry for 116 YSOs identified in Sh 2-305
table5.dat 87 28 Optical data for 28 YSOs
table6.dat 48 96 Stellar parameters of selected 98 YSOs derived
using the SED fitting analysis
table8.dat 33 25 Properties of the clumps identified using
the Herschel column density map
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See also:
II/183 : UBVRI Photometric Standards (Landolt 1992)
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
II/328 : AllWISE Data Release (Cutri+ 2013)
VI/139 : Herschel Observation Log (Herschel Science Centre, 2013)
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
I/347 : Distances to 1.33 billion stars in Gaia DR2 (Bailer-Jones+, 2018)
J/ApJ/428/693 : Rosette Nebula & Maddalena Cloud structures (Williams+ 1994)
J/A+A/397/177 : IR star clusters and stellar groups catalog (Bica+, 2003)
J/A+A/400/533 : New infrared star clusters in southern MW (Dutra+, 2003)
J/AJ/132/1669 : Wide-field CCD phot. around 9 open clusters (Sharma+, 2006)
J/A+A/462/L17 : Dense cores in interstellar molecular clouds (Alves+, 2007)
J/ApJ/667/963 : NIR photometry of Carina nebula (Sanchawala+, 2007)
J/ApJ/675/491 : Lynds 988e JHKs and IRAC photometry (Allen+, 2008)
J/ApJ/674/336 : Spitzer observations of NGC 1333 (Gutermuth+, 2008)
J/MNRAS/384/1675 : BVRIc photometry of Stock 8 (Jose+, 2008)
J/ApJ/688/1142 : Star formation in W5: Spitzer observations (Koenig+, 2008)
J/MNRAS/383/1241 : UBVIc photometry of cluster Berkeley 59 (Pandey+, 2008)
J/MNRAS/396/964 : T Tauri in and around bright-rimmed clouds (Chauhan+, 2009)
J/A+A/501/563 : HKs photometry in the Arches cluster (Espinoza+, 2009)
J/ApJS/181/321 : Properties of Spitzer c2d dark clouds (Evans+, 2009)
J/ApJS/184/18 : Spitzer survey of young stellar clusters (Gutermuth+, 2009)
J/AJ/141/123 : Molecular clouds associated with HII regions (Azimlu+, 2011)
J/MNRAS/415/1202 : BVI photometry in W5E HII region (Chauhan+, 2011)
J/AJ/143/41 : UBVIc CCD phot. of star clusters Tr14 and Tr16 (Hur+, 2012)
J/ApJ/755/20 : YSOs population of Sh2-294 with Spitzer/IRAC (Samal+, 2012)
J/PASJ/64/107 : Multiwavelength study of NGC 281 complex (Sharma+, 2012)
J/MNRAS/432/3445 : YSOs on HII complex Sh2-252 (Jose+, 2013)
J/ApJ/764/172 : UBVRI photometry of stars toward NGC 1931 (Pandey+, 2013)
J/A+A/549/A130 : YSOs in Herschel-Hi-GAL survey (Veneziani+, 2013)
J/MNRAS/430/3350 : Proper motions and membership in NGC 3766 (Yadav+, 2013)
J/MNRAS/439/3719 : Embedded clusters infrared photometry (Chavarria+, 2014)
J/ApJ/787/107 : Spatial structure of young clusters. I. (Kuhn+, 2014)
J/A+A/567/A109 : Carina nebula optically identified YSOs (Kumar+, 2014)
J/MNRAS/443/3218 : NGC 7538 IRS 1-3 and IRS 9 sources (Mallick+, 2014)
J/MNRAS/443/1614 : YSOs in BRC 5, 7 and 39 (Panwar+, 2014)
J/ApJ/822/49 : Cand. YSOs in AFGL 333 with NEWFIRM & Spitzer (Jose+, 2016)
J/A+A/585/A101 : MW global survey of star clusters. V. (Kharchenko+, 2016)
J/AJ/151/126 : Phot. of YSOs in eight bright-rimmed clouds (Sharma+, 2016)
J/MNRAS/461/2502 : Multiwavelength study of HII region S311 (Yadav+, 2016)
J/MNRAS/468/2684 : IC1805 YSOs (Panwar+, 2017)
J/MNRAS/467/2943 : NGC 7538 region YSOs (Sharma+, 2017)
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- Seq [1/137] Sequential running number of the star
5- 14 F10.6 deg RAdeg [112.43/112.62] Right Ascension (J2000)
16- 25 F10.6 deg DEdeg [-18.63/-18.44] Declination (J2000)
27- 32 F6.3 mas plx [-0.23/0.87] Gaia DR2 parallax
34- 38 F5.3 mas e_plx [0.02/0.8] Uncertainty in plx
40- 45 F6.3 mas/yr pmRA [-2.45/-1.02] Gaia DR2 proper motion in RA
47- 51 F5.3 mas/yr e_pmRA [0.02/0.9] Uncertainty in pmRA
53- 57 F5.3 mas/yr pmDE [1.35/3.17] Gaia DR2 proper motion in Dec
59- 63 F5.3 mas/yr e_pmDE [0.03/1] Uncertainty in pmDE
65- 70 F6.3 mag Gmag [12.45/20.33] Gaia DR2 G band magnitude
72- 77 F6.3 mag Gbp-Grp [1.19/]?=99 Gaia DR2 (Gbp-Grp) color index
79- 81 I3 % Mm [81/100] Membership probability, Equation 9
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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 I3 --- ID [1/116] IR sequential running number of the YSO
5- 14 F10.6 deg RAdeg [112.36/112.64] Right Ascension (J2000)
16- 25 F10.6 deg DEdeg [-18.67/-18.43] Declination (J2000)
27- 33 F7.3 mag Jmag [10.85/17.98]? TIRSPEC J band magnitude
35- 41 F7.4 mag e_Jmag [0.003/0.2]? Uncertainty in Jmag
43- 48 F6.3 mag Hmag [8.02/17.64]? TIRSPEC H band magnitude
50- 55 F6.4 mag e_Hmag [0.004/0.2]? Uncertainty in Hmag
57- 62 F6.3 mag Kmag [6.05/16.18]? TIRSPEC K band magnitude
64- 69 F6.4 mag e_Kmag [0.003/0.2]? Uncertainty in Kmag
71- 76 F6.3 mag [3.6] [8.12/14.93]? Spitzer/IRAC 3.6um band magnitude
78- 82 F5.3 mag e_[3.6] [0.03/0.2]? Error in 3.6um
84- 89 F6.3 mag [4.5] [7.05/14.61]? Spitzer/IRAC 4.5um band magnitude
91- 95 F5.3 mag e_[4.5] [0.03/4.1]? Error in 4.5um
97-102 F6.3 mag W1mag [0.26/15.38]? WISE W1 magnitude (3.35um)
104-108 F5.3 mag e_W1mag [0.02/2.75]? Uncertainty in W1mag
110-115 F6.3 mag W2mag [0.41/15.63]? WISE W2 magnitude (4.6um)
117-122 F6.3 mag e_W2mag [0.01/0.3]? Uncertainty in W2mag
124-129 F6.3 mag W3mag [0.10/11.64]? WISE W3 magnitude (11.6um)
131-136 F6.3 mag e_W3mag [0.01/0.4]? Uncertainty in W3mag
138-143 F6.4 mag W4mag [0.003/8.7]? WISE W4 magnitude (22.1um)
145-150 F6.3 mag e_W4mag [0.02/0.5]? Uncertainty in W4mag
152-153 A2 --- Cl YSO Class (I=20 occurrences, II=96 occurrences)
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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 I3 --- ID [2/113] IR identifier as in Table 4
5- 14 F10.6 deg RAdeg [112.39/112.64] Right Ascension (J2000)
16- 25 F10.6 deg DEdeg [-18.67/-18.45] Declination (J2000)
27- 32 F6.3 mag Vmag [14.53/21.45] V band magnitude
34- 38 F5.3 mag e_Vmag [0.003/0.09] Uncertainty in Vmag
40- 45 F6.3 mag (U-B) [-0.3/0.8]? (U-B) color index
47- 51 F5.3 mag e_(U-B) [0.01/0.3]? Uncertainty in (U-B)
53- 57 F5.3 mag (B-V) [0.9/2.1]? (B-V) color index
59- 63 F5.3 mag e_(B-V) [0.008/0.2]? Uncertainty in (B-V)
65- 69 F5.3 mag (V-R) [0.4/1.8] (V-R) color index
71- 75 F5.3 mag e_(V-R) [0.004/0.2] Uncertainty in (V-R)
77- 81 F5.3 mag (V-I) [1.2/3.3] (V-I) color index
83- 87 F5.3 mag e_(V-I) [0.005/0.1] Uncertainty in (V-I)
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Byte-by-byte Description of file: table6.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- ID [1/116] IR identifier as in Table 4
5- 6 I2 --- Nsed [5/14] Number of points in SED
8- 9 A2 --- Cl YSO Class (I=12 occurrences; II=84 occurrences)
11- 14 F4.1 --- chi2 [0/85.4] Minimised χ2 value
16- 18 F3.1 kpc Dist [3.3/3.8] Distance
20- 22 F3.1 kpc e_Dist [0/0.3] Uncertainty in Dist
24- 27 F4.1 mag Av [2.2/23.1] Extinction, line of sight to YSO
29- 31 F3.1 mag e_Av [0.1/7.7] Uncertainty in Av
33- 35 F3.1 Myr Age [0/5.8] Age of the YSO
37- 39 F3.1 Myr e_Age [0/3.5] Uncertainty in Age
41- 44 F4.1 Msun Mstar [0.8/16.2] Mass of the YSO
46- 48 F3.1 Msun e_Mstar [0/3.3] Uncertainty in Mstar
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Byte-by-byte Description of file: table8.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- Seq [1/25] Herschel clump identifier
4- 5 I2 h RAh Hour of Right Ascension (J2000)
7- 8 I2 min RAm Minute of Right Ascension (J2000)
10- 13 F4.1 s RAs Second of Right Ascension (J2000)
15 A1 --- DE- Sign of the Declination (J2000)
16- 17 I2 deg DEd Degree of Declination (J2000)
19- 20 I2 arcmin DEm Arcminute of Declination (J2000)
22- 23 I2 arcsec DEs Arcsecond of Declination (J2000)
25- 28 F4.2 pc Rad [0.28/1.32] Clump Radius
30- 33 I4 Msun Mclump [35/1565] Clump mass
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 06-Aug-2021