J/A+A/622/A38 IRAS05168+3634 star-forming region stellar content (Azatyan, 2019)
Investigation of the stellar content in the IRAS 05168+3634 star-forming region.
Azatyan N.M.
<Astron. Astrophys., 622, A38 (2019)>
=2019A&A...622A..38A 2019A&A...622A..38A (SIMBAD/NED BibCode)
ADC_Keywords: Infrared sources ; Stars, pre-main sequence ; Photometry, infrared
Keywords: stars: pre-main sequence - stars: luminosity function -
mass function - infrared: stars - radiative transfer -
ISM: individual: IRAS 05168+3634
Abstract:
Aims. We report the investigation results of the structure and content
of a molecular cloud surrounding the source IRAS 05168+3634 (also
known as Mol 9). Methods. We present a photometric analysis using the
data of J, H, K UKIDSS, [3.6], [4.5]µm Spitzer-IRAC and 3.4, 4.6,
12, 22µm WISE databases. A multi-color criteria was used to
identify the candidates of young stellar objects (YSOs) in the
molecular cloud; in addition to IRAS 05168+3634, there are four IRAS
sources embedded in the same molecular cloud. Color-magnitude diagrams
and the K luminosity function (KLF) were used to determine the basic
parameters of stellar objects (spectral classes, masses, ages). To
study the YSOs with longer wavelength photometry the radiative
transfer models were used. Results. Based on color-color and
color-magnitude diagrams, we identified a rich population of embedded
YSO candidates with infrared excess (Class 0/I and Class II) and their
characteristics in a quite large molecular cloud located in a region
of 24 arcmin radius. The molecular cloud includes 240 candidates of
YSOs within the radii of subregions around five IRAS sources. The
local distribution of identified YSOs in the molecular cloud
frequently shows elongation and subclustering. The observed young
subregions and parental molecular cloud morphologies are similar,
especially when only the youngest Class I/0 sources are considered.
The color-magnitude diagrams of the subregions suggest a very young
stellar population. We construct the KLF of the subregions except for
the IRAS 05162+3639 region and it shows unusually low values for
α slope: 0.12-0.21. According to the values of the slopes of the
KLFs, the age of the subregions can be estimated at 0.1-3Myr. The
spectral energy distributions (SEDs) are constructed for 45 Class I
and 75 Class II evolutionary stage YSOs and the received parameters of
these YSOs are well correlated with the results obtained by other
methods. According to the results of SED fitting tool, the sources
IRAS 05184+3635, IRAS 05177+3636, and IRAS 05162+3639 can be
classified as Class I evolutionary stage objects. IRAS 05168+3634 and
IRAS 05156+3643 can be classified as flat-spectrum objects.
Description:
For our study we used the data covering a wide infrared (IR) range
from NIR to far-infrared (FIR) wavelengths. The first is the archival
NIR photometric data and images in the J, H, and K bands of the
Galactic Plane Survey DR6 (GPS; Lucas et al., 2008MNRAS.391..136L 2008MNRAS.391..136L,
Cat. II/316) with a resolution of 0.1"/pix, which is one of the five
surveys of the UKIRT Infrared Deep Sky Survey (UKIDSS).
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
tablea1.dat 171 240 Members of subregions with NIR and MIR photometry
tablea2.dat 161 30 Members of subregions with FIR photometry
tablea3.dat 155 91 Parameters derived from Robitaille et al.
(2007ApJS..169..328R 2007ApJS..169..328R) models SED fitting for
two distances
--------------------------------------------------------------------------------
See also:
II/316 : UKIDSS-DR6 Galactic Plane Survey (Lucas+ 2012)
Byte-by-byte Description of file: tablea1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 15 A15 --- Region Region
17- 19 I3 --- ID [1/240] ID number in final list of
sub-region members
20 A1 --- n_ID [ab] Note on ID (1)
23 I1 h RAh Right ascension (J2000) from UKIDSS survey
25- 26 I2 min RAm Right ascension (J2000) from UKIDSS survey
28- 32 F5.2 s RAs Right ascension (J2000) from UKIDSS survey
33 A1 --- DE- Declination sign (J2000) from UKIDSS survey
34- 35 I2 deg DEd Declination (J2000) from UKIDSS survey
37- 38 I2 arcmin DEm Declination (J2000) from UKIDSS survey
40- 44 F5.2 arcsec DEs Declination (J2000) from UKIDSS survey
46- 51 F6.3 mag Jmag ?=- J magnitude
53- 57 F5.3 mag e_Jmag ?=- rms uncertainty on Jmag
59- 64 F6.3 mag Hmag ?=- H magnitude
66- 70 F5.3 mag e_Hmag ? rms uncertainty on Hmag
72- 77 F6.3 mag Kmag K magnitude
79- 83 F5.3 mag e_Kmag rms uncertainty on Kmag
85- 90 F6.3 mag [3.6]mag ?=- IRAC 3.6um magnitude
92- 96 F5.3 mag e_[3.6]mag ? rms uncertainty on [3.6]mag
98-103 F6.3 mag [4.5]mag ?=- IRAC 4.5um magnitude
105-109 F5.3 mag e_[4.5]mag ? rms uncertainty on [4.5]mag
111-116 F6.3 mag W1mag ?=- WISE W1 magnitude
118-122 F5.3 mag e_W1mag ? rms uncertainty on W1mag
124-129 F6.3 mag W2mag ?=- WISE W2 magnitude
131-135 F5.3 mag e_W2mag ? rms uncertainty on W2mag
137-142 F6.3 mag W3mag ?=- WISE W3 magnitude
144-148 F5.3 mag e_W3mag ? rms uncertainty on W3mag
150-154 F5.3 mag W4mag ?=- WISE W4 magnitude
156-160 F5.3 mag e_W4mag ? rms uncertainty on W4mag
162-171 A10 --- Class Final classification of YSOs according to
color-color diagrams
--------------------------------------------------------------------------------
Note (1): Notes as follows:
a = Objects that are located to the left of ZAMS in one color-magnitude diagram
b = Objects that are located to the left of ZAMS in both color-magnitude
diagrams
--------------------------------------------------------------------------------
Byte-by-byte Description of file: tablea2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- ID Number of sub-regions members taken from
Table A.1
5- 21 A17 --- Name Names of IRAS and MSX source
24- 26 I3 mJy F8.28 ? MSX 8.28um measured flux
28- 29 I2 mJy e_F8.28 ? rms uncertainty on F8.28
31- 34 I4 mJy F12.13 ? MSX 12.13um measured flux
36- 38 I3 mJy e_F12.13 ? rms uncertainty on F12.13
40- 43 I4 mJy F14.65 ? MSX 14.65um measured flux
45- 47 I3 mJy e_F14.65 ? rms uncertainty on F14.65
49- 52 I4 mJy F21.3 ? MSX 21.3um measured flux
54- 56 I3 mJy e_F21.3 ? rms uncertainty on F21.3
58- 61 I4 mJy F12 ? IRAS 12um measured flux
63- 65 I3 mJy e_F12 ? rms uncertainty on F12
67- 70 I4 mJy F25 ? IRAS 25um measured flux
72- 74 I3 mJy e_F25 ? rms uncertainty on F25
76- 81 I6 mJy F60 ? IRAS 60um measured flux
83- 87 I5 mJy e_F60 ? rms uncertainty on F60
89- 94 I6 mJy F100 ? IRAS 100um measured flux
96-100 I5 mJy e_F100 ? rms uncertainty on F100
102-105 I4 mJy F70 ? Herschel PACS 70um measured flux
107-113 F7.3 mJy e_F70 ? rms uncertainty on F70
114 A1 --- neF70 [a] Note on e_F70 (1)
118-122 I5 mJy F160 ? Herschel PACS 160um measured flux
124-131 F8.3 mJy e_F160 ? rms uncertainty on F160
132 A1 --- neF160 [b] Note on e_F160 (1)
134-137 I4 mJy F250 ? Herschel SPIRE 250um measured flux
139-141 I3 mJy e_F250 ? rms uncertainty on F250
143-148 F6.1 mJy F350 ? Herschel SPIRE 350um measured flux
150-152 I3 mJy e_F350 ? rms uncertainty on F350
154-157 I4 mJy F500 ? Herschel SPIRE 500um measured flux
159-161 I3 mJy e_F500 ? rms uncertainty on F500
--------------------------------------------------------------------------------
Note (1): Notes as follows:
a = Fluxes taken from Herschel PACS: Extended source list catalog in
blue band (70)
b = Fluxes taken from Herschel PACS: Extended source list catalog in
red band (160)
--------------------------------------------------------------------------------
Byte-by-byte Description of file: tablea3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 15 A15 --- Region Region
17- 19 I3 --- ID ID number of sub-regions members
taken from Table A.1,
21- 24 F4.1 mag Av1.88 ?=- Interstellar extinction for
distance=1.88kpc (1)
26- 28 F3.1 mag e_Av1.88 ? rms uncertainty on Av1.88 (1)
30- 33 F4.1 mag Av6.1 Interstellar extinction for
distance=6.1kpc (1)
35- 37 F3.1 mag e_Av6.1 rms uncertainty on Av6.1 (1)
39- 41 F3.1 [yr] logAge1.88 ?=- Stellar age for distance=1.88kpc (1)
43- 45 F3.1 [yr] e_logAge1.88 ? rms uncertainty on logAge1.88 (1)
47- 49 F3.1 [yr] logAge6.1 Stellar age for distance=6.1kpc (1)
51- 53 F3.1 [yr] e_logAge6.1 rms uncertainty on logAge6.1 (1)
55- 57 F3.1 Msun Mass1.88 ?=- Stellar mass for distance=1.88kpc (1)
59- 61 F3.1 Msun e_Mass1.88 ? rms uncertainty on Mass1.88 (1)
63- 65 F3.1 Msun Mass6.1 Stellar mass for distance=6.1kpc (1)
67- 69 F3.1 Msun e_Mass6.1 rms uncertainty on Mass6.1 (1)
71- 73 F3.1 [K] logT1.88 ?=- Temperature for distance=1.88kpc (1)
75- 77 F3.1 [K] e_logT1.88 ? rms uncertainty on logT1.88 (1)
79- 81 F3.1 [K] logT6.1 Temperature for distance=6.1kpc (1)
83- 85 F3.1 [K] e_logT6.1 rms uncertainty on logT6.10 (1)
87- 90 F4.1 [Msun/yr] MdotE1.88 ?=- Envelope accretion rate
for distance=1.88kpc (1)
92- 94 F3.1 [Msun/yr] e_MdotE1.88 ? rms uncertainty on MdotE1.88 (1)
96- 99 F4.1 [Msun/yr] MdotE6.1 Envelope accretion rate
for distance=6.1kpc (1)
101-103 F3.1 [Msun/yr] e_MdotE6.1 rms uncertainty on MdotE6.1 (1)
105-109 F5.1 [Msun/yr] MdotD1.88 ?=- Disk accretion rate
for distance=1.88kpc (1)
111-114 F4.1 [Msun/yr] e_MdotD1.88 ? rms uncertainty on MdotD1.88 (1)
116-120 F5.1 [Msun/yr] MdotD6.1 Disk accretion rate
for distance=6.1kpc (1)
122-125 F4.1 [Msun/yr] e_MdotD6.1 rms uncertainty on MdotD6.1 (1)
127-130 F4.1 [Lsun] LTotal1.88 ?=- Total luminosity for
distance=1.88kpc (1)
132-134 F3.1 [Lsun] e_LTotal1.88 ? rms uncertainty on LTotal1.88 (1)
136-138 F3.1 [Lsun] LTotal6.1 Total luminosity for distance=6.1kpc (1)
140-142 F3.1 [Lsun] e_LTotal6.1 rms uncertainty on LTotal6.1 (1)
144-147 I4 --- Nfit1.88 ?=- Number of fitting models for
distance=1.88kpc
149-152 I4 --- Nfit6.1 Number of fitting models for
distance=6.1kpc
154-155 I2 --- Ndata Number of input fluxes
--------------------------------------------------------------------------------
Note (1): weighted means and the standard deviations of parameters obtained by
fitting tool for all models with chi2-Chi2best<3N
at two distances: 1.88 and 6.1kpc.
--------------------------------------------------------------------------------
History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 02-Apr-2019