J/A+A/674/A64 FIFI-LS spectroscopy of Gy 3-7 in outer Galaxy (Le+, 2023)
Far-infrared line emission from the outer Galaxy cluster Gy 3-7
with SOFIA/FIFI-LS: Physical conditions and UV fields
Le N., Karska A., Figueira M., Sewilo M., Mirocha A., Fischer C.,
Kazmierczak-Barthel M., Klein R., Gawronski M., Koprowski M., Kowalczyk K.,
Fischer W.J., Menten K.M., Wyrowski F., Koenig C., Kristensen L.E.
<Astron. Astrophys. 674, A64 (2023)>
=2023A&A...674A..64L 2023A&A...674A..64L (SIMBAD/NED BibCode)
ADC_Keywords: YSOs ; Photometry, infrared ; Spectra, infrared ; Stars, masers
Keywords: stars: formation - stars: protostars - ISM: jets and outflows -
ISM: molecules
Abstract:
Far-infrared line emission provides key information about the gas
cooling and heating due to shocks and UV radiation associated with
the early stages of sta r formation. Gas cooling via far-infrared
lines might depend, however, on metallicity.
We aim to quantify the far-infrared line emission, determine the
spatial distribution of CO rotational temperature, ultraviolet (UV)
radiation field, and H2 number density toward the embedded cluster Gy
3-7 in the CMa-l224 star-forming region, whose metallicity is expected
to be intermediate between the Large Magellanic Cloud and the Solar
neighborhood. By comparing the total luminosities of CO and [OI]
toward Gy 3-7 with values found for low- and high-mass protostars
extending over a broad range of metallicities, we also aim to identify
the possible effects of metallicity on the far-infrared line cooling
within our Galaxy.
We study SOFIA/FIFI-LS spectra of Gy 3-7 covering several CO
transitions from J=14-13 to 31-30, the OH doublet at 79um, the [OI]
63.2 and 145.5um, and the [CII] 158um lines. The field-of-view covers
a 2'x1' region with a resolution of ∼7"-18".
The spatial extent of CO high-J (Jup≥14) emission resembles that of
the elongated 160 um continuum emission detected with Herschel, but
its peaks are offset from the positions of the dense cores. The [OI]
lines at 63.2um and 145.5um follow a similar pattern, but their peaks
are found closer to the positions of the cores. CO transitions from
J=14-13 to J=16-15 are detected throughout the cluster and show a
median rotational temperature of 170±30K on Boltzmann diagrams.
Comparison to other protostars observed with Herschel shows a good
agreement with intermediate-mass sources in the inner Galaxy. Assuming
an origin of the [OI] and high-J CO emission in UV-irradiated
C-shocks, we obtain pre-shock H2 number densities of
104-105cm-3 and UV radiation field strengths of 0.1-10 Habing
fields (G0).
Far-IR line observations reveal on-going star formation in Gy 3-7,
dominated by intermediate-mass Class 0/I young stellar objects. The
ratio of molecular-to-atomic far-IR line emission shows a decreasing
trend with bolometric luminosities of the protostars. However, it does
not indicate that the low-metallicity has an impact on the line
cooling in Gy 3-7.
Description:
Observations of the Gy 3-7 cluster obtained with SOFIA/FIFI-LS in
far-infrared wavelength allow us to quantify the characteristics of
gas cooling and to test possible impact of metallicity on line cooling
in the region.
Objects:
-------------------------------------------
RA (2000) DE Designation(s)
-------------------------------------------
07 09 20.4 -10 50 28.4 Gy 3-7 Core A
07 09 21.9 -10 50 35. Gy 3-7 Core B
-------------------------------------------
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
list.dat 133 10 List of datacubes
fits/* . 10 Individual datacubes
table2.dat 64 8 CO rotational temperature, the number of emitting
molecules, and total line luminosities of CO and
[OI] lines toward dense cores in Gy 3-7 and
IM YSOs from Matuszak et al. (2015A&A...578A..20M 2015A&A...578A..20M)
table4.dat 47 12 Physical parameters for a subset of YSO candidates
with at least 5 photometric data points
tablea1.dat 58 7 Parameters of the 22 GHz H2O maser lines detected
toward CMa l224 with RT4
tableb1.dat 28 9 Flux SOFIA FIFI-LS toward the two dense cores
within a beam size of 20"
tablec1.dat 177 15 *Multi-wavelength photometry of YSO candidates in
the IRAS field.
tabled1.dat 30 10 CO rotational temperature and number of emitting
molecules for HM YSOs, derived by fitting the
rotational diagram of CO using all and only
four available CO transitions
tabled2.dat 96 29 Far-IR line cooling luminosity of the sample
in the Milky Way (MW), LMC, and SMC used to
compare with results of this study
--------------------------------------------------------------------------------
Note on tablec1.dat: The columns represent the 2MASS JHKs, Spitzer IRAC 3.6
and 4.5 um, AllWISE, Herschel PACS and SPIRE.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: list.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 9 F9.5 deg RAdeg Right Ascension of center (J2000)
10- 18 F9.5 deg DEdeg Declination of center (J2000)
20- 21 I2 --- Nx Number of pixels along X-axis
23- 24 I2 --- Ny Number of pixels along Y-axis
26- 27 I2 --- Nz Number of slices
29- 47 A19 "datime" Obs.date Observation date
49- 56 F8.4 0.1nm bWAVE Lower value of wavelength interval
58- 65 F8.4 0.1nm BWAVE Upper value of wavelength interval
67- 76 F10.8 0.1nm dWAVE Wavelength resolution
78- 80 I3 Kibyte size Size of FITS file
82- 97 A16 --- FileName Name of FITS file, in subdirectory fits
99-133 A35 --- Title Title of the FITS file
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1 A1 --- Group [AB] Group (1)
3- 10 A8 --- Source Source name
12- 14 I3 K Trot CO rotational temperature (2)
16- 17 I2 K e_Trot Uncertainty of rotational temperature (2)
19- 23 F5.2 --- logNtot Base-10 logarithm of total number of
emitting molecules (2)
25- 28 F4.2 --- e_logNtot Uncertainty of logNtot (2)
30- 35 F6.2 mLsun LCO Total CO luminosity
in warm component (3)
37- 41 F5.2 mLsun e_LCO Uncertainty of LCO (3)
43- 48 F6.2 mLsun LOI63 Luminosity of [O I] 63 um line
50- 53 F4.2 mLsun e_LOI63 Uncertainty of LOI63
55- 59 F5.2 mLsun LOI145 Luminosity of [O I] 145 um line
61- 64 F4.2 mLsun e_LOI145 Uncertainty of LOI145
--------------------------------------------------------------------------------
Note (1): Group as follows:
A = Dense cores in Gy 3-7
B = IM YSOs in the inner Milky Way
Note (2): Trot and Ntot calculated using only CO 14-13, CO 16-15, CO 18-17,
and CO 22-21 transitions for more direct comparisons with the cores in
Gy 3-7.
Note (3): The CO line luminosity in the "warm" component is obtained
using all transitions reported in Matuszak et al. (2015A&A...578A..20M 2015A&A...578A..20M)
with Jup from 14 to 24 (see Section 4.2)
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 2 I2 --- ID Source identification number
4- 10 A7 --- ModelSet Model Set name (G1)
12- 17 A6 --- Class YSO class as determined from the SED
fitting (see Sect. 4.5)
19- 22 F4.1 Rsun R* Stellar radius
24- 27 I4 K T* Stellar temperature
29- 33 F5.1 Lsun L* Stellar Luminosity
35- 37 I3 Msun M* ?=- Stellar mass (1)
39- 42 F4.2 Myr Age ?=- Stellar age (1)
44- 47 A4 --- Note Note for YSO (2)
--------------------------------------------------------------------------------
Note (1): We provide stellar masses (M*) and ages only for sources with
reliable estimation of these parameters (see text for details).
Note (2): IDs of the YSO candidates in Gy 3-7
identified by Tapia et al. (1997AJ....113.1769T 1997AJ....113.1769T), see Figure 1
-------------------------------------------------------------------------------
Byte-by-byte Description of file: tablea1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1 A1 --- Group [AB] Group (1)
3- 13 A11 --- Obs.date Observation date
15- 19 F5.2 km/s Vp Central velocity of of the water maser line
21- 24 F4.2 km/s e_Vp Uncertainty of Vp
26- 31 F6.2 Jy Sp Flux density peak
33- 36 F4.2 Jy e_Sp Uncertainty of Sp
38- 41 F4.2 km/s FWHM FWHM
43- 47 F5.3 km/s e_FWHM Uncertainty of FWHM
49- 53 F5.2 Jy.km/s intSdV Integrated flux density
55- 58 F4.2 Jy.km/s e_intSdV Uncertainty of intSdV
--------------------------------------------------------------------------------
Note (1): Group as follows:
A = Gy 3-7
B = RAS 07069-1026
-------------------------------------------------------------------------------
Byte-by-byte Description of file: tableb1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 6 F6.2 um lambda Wavelength
8- 12 F5.2 10-16W/m2 FA Flux at core A
14- 17 F4.2 10-16W/m2 e_FA Uncertainty of FA
19- 23 F5.2 10-16W/m2 FB ?=- Flux at core B
25- 28 F4.2 10-16W/m2 e_FB ?=- Uncertainty of FB
--------------------------------------------------------------------------------
Byte-by-byte Description of file: tablec1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 2 I2 --- ID Source identification number
4- 12 F9.5 deg RAdeg Right Ascension (J2000)
14- 22 F9.5 deg DEdeg Declination (J2000)
24- 28 F5.2 mJy SJ ?=- 2MASS J flux
30- 33 F4.2 mJy e_SJ ?=- 2MASS J flux error
35- 39 F5.2 mJy SH 2MASS H flux
41- 44 F4.2 mJy e_SH 2MASS H flux error
46- 50 F5.2 mJy SKs 2MASS Ks flux
52- 55 F4.2 mJy e_SKs 2MASS Ks flux error
57- 61 F5.2 mJy S3.6 ?=- IRAC 3.6um flux
63- 66 F4.2 mJy e_S3.6 ?=- IRAC 3.6um flux error
68- 72 F5.2 mJy S4.5 ?=- IRAC 4.5um flux
74- 77 F4.2 mJy e_S4.5 ?=- IRAC 4.5um flux error
79- 83 F5.2 mJy SW1 ?=- AllWISE 3.4um (W1) flux
85- 88 F4.2 mJy e_SW1 ?=- AllWISE 3.4um (W1) flux error
90- 95 F6.2 mJy SW2 ?=- AllWISE 4.6um (W2) flux
97-100 F4.2 mJy e_SW2 ?=- AllWISE 4.6um (W2) flux error
102-108 F7.2 mJy SW3 ?=- AllWISE 12um (W3) flux
110-114 F5.2 mJy e_SW3 ?=- AllWISE 12um (W3) flux error
116-123 F8.2 mJy SW4 ?=- AllWISE 22um (W4) flux
125-130 F6.2 mJy e_SW4 ?=- AllWISE 22um (W4) flux error
132-136 F5.1 Jy S70 ?=- PACS 70um flux
138-140 F3.1 Jy e_S70 ?=- PACS 70um flux error
142-147 F6.1 Jy S160 ?=- PACS 160um flux
149-151 F3.1 Jy e_S160 ?=- PACS 160um flux error
153-155 I3 Jy S250 ?=- SPIRE 250um flux
157-159 F3.1 Jy e_S250 ?=- SPIRE 250um flux error
161-164 F4.1 Jy S350 ?=- SPIRE 350um flux
166-168 F3.1 Jy e_S350 ?=- SPIRE 350um flux error
170-173 F4.1 Jy S500 ?=- SPIRE 500um flux
175-177 F3.1 Jy e_S500 ?=- SPIRE 500um flux error
--------------------------------------------------------------------------------
Byte-by-byte Description of file: tabled1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 11 A11 --- Source Source name
13- 15 I3 K Trot4 Rotational temperatures calculated using 4 CO
transitions with Jup = (14, 16, 17, 22)
17- 18 I2 K e_Trot4 Uncertainty in Trot4
20- 22 I3 K Trota Rotational temperatures calculated using all
detected CO transitions, data is adopted from
Karska et al. (2014A&A...562A..45K 2014A&A...562A..45K).
24- 25 I2 K e_Trota Uncertainty in Trota
27- 30 F4.1 % Diff The relative difference between Trot4 and
Trota is taken as |1-Trot4/Trota|*100
--------------------------------------------------------------------------------
Byte-by-byte Description of file: tabled2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1 A1 --- Group [ABCD] Group (1)
3- 23 A21 --- Source Source name
25- 30 F6.3 kpc D Distance
32- 35 F4.2 kpc e_D ?=- Distance error
37- 38 I2 --- r_D Reference of distances (G2)
40- 44 F5.2 kpc RGC ?=- Galactocentric radius (2)
46- 48 F3.1 --- Z Metallicity compared to Zsun (3)
50- 52 F3.1 [Lsun] logLbol Based-10 logarithm of bolometric to
solar luminosity ratio
54- 55 I2 --- r_logLbol Reference of logLbol (G2)
57- 62 F6.1 10-2Lsun LCO Luminosty of CO in warm component (4)
64- 68 F5.1 10-2Lsun e_LCO ?=- Uncertainty of LCO
70- 75 F6.1 10-2Lsun LOI Luminosity of [OI] line (5)
77- 81 F5.1 10-2Lsun e_LOI ?=- Uncertainty of LOI
83- 88 F6.3 --- Lratio Luminosity ratio of CO to [OI]
90- 93 F4.1 --- e_Lratio ?=- Uncertainty of Lratio
95- 96 I2 --- refLline Reference of the line luminosities (G2)
--------------------------------------------------------------------------------
Note (1): Group as follows:
A = LMC YSO
B = SMC YSO
C = MW IM YSOs
D = MW HM YSOs
Note (2): Galactocentric radius toward the sources in the Milky Way is
calculated using the information from their coordinate and distance to the
Sun, assuming the distance from the Sun to the Galactic center is 8.34kpc.
Note (3): Metallicity towards the sources in the Milky Way is calculated using
the relation of O/H gradients inferred from the HII regions:
12+log(O/H)=-0.0446RGC+8.962 (Balser et al. 2011ApJ...738...27B 2011ApJ...738...27B)
Note (4): Total far-IR luminosity of CO derived from the rotational diagram
fitting
Note (5): Total far-IR luminosity of [O I] calculated by summing the luminosity
of [O i] lines at 63 and 145um
--------------------------------------------------------------------------------
Global notes:
Note (G1): Model set names:
----------------------------------------------------------------------------
Model # of Compoments Group
sources
----------------------------------------------------------------------------
s---s-i 4 star -
sp--s-i 2 star + passive disk; Rinner = Rsub d
sp--h-i 4 star + passive disk; variable Rinner d
s-pbhmi 1 star + power-law envelope + cavity + medium;
variable Rinner e
spubsmi 1 star + passive disk + Ulrich envelope + cavity + medium;
Rinner = Rsub d+e
----------------------------------------------------------------------------
The model set names are from Robitaille (2017A&A...600A..11R 2017A&A...600A..11R).
Seven characters in the model set names indicate which component is present;
they are (in order): s: star; p: passive disk,
p or u: power-law or Ulrich envelope; b: bipolar cavities; h: inner hole;
m: ambient medium; and i: interstellar dust.
A dash (-) is used when a component is absent.
Rinner is the inner radius for the disk, envelope, and the ambient medium -
when one or more of these components are present.
Rsub is the dust sublimation radius.
---------------------------------------------------------------------------
Note (G2): List of reference for the distance and luminosity of CO and OI lines
as follows:
1 = Pietrzynski et al. (2013Natur.495...76P 2013Natur.495...76P)
2 = Graczyk et al. (2014ApJ...780...59G 2014ApJ...780...59G)
3 = Purser et al. (2021MNRAS.504..338P 2021MNRAS.504..338P)
4 = Wilson et al. (2005A&A...430..523W 2005A&A...430..523W)
5 = Liseau et al. (1992A&A...265..577L 1992A&A...265..577L)
6 = Shevchenko & Yakubov (1989SvA....33..370S 1989SvA....33..370S)
7 = Minier et al. (2009A&A...501L...1M 2009A&A...501L...1M)
8 = Xu et al. (2009ApJ...693..413X 2009ApJ...693..413X)
9 = Rygl et al. (2012A&A...539A..79R 2012A&A...539A..79R)
10 = Immer et al. (2013A&A...553A.117I 2013A&A...553A.117I)
11 = Kuchar & Bania (1994ApJ...436..117K 1994ApJ...436..117K)
12 = Neckel (1978A&A....69...51N 1978A&A....69...51N)
13 = Moscadelli et al. (2009ApJ...693..406M 2009ApJ...693..406M)
14 = Hachisuka et al. (2006ApJ...645..337H 2006ApJ...645..337H)
15 = Motogi et al. (2011PASJ...63...31M 2011PASJ...63...31M)
16 = Oliveira et al. (2019MNRAS.490.3909O 2019MNRAS.490.3909O)
17 = Navarete et al. (2015MNRAS.450.4364N 2015MNRAS.450.4364N)
18 = Stanke et al. (2000A&A...355..639S 2000A&A...355..639S)
19 = Butner et al. (1990ApJ...364..164B 1990ApJ...364..164B)
20 = Giannini et al. (2005A&A...433..941G 2005A&A...433..941G)
21 = Johnstone et al. (2010A&A...521L..41J 2010A&A...521L..41J)
22 = Urquhart et al. (2012MNRAS.420.1656U 2012MNRAS.420.1656U)
23 = van Dishoeck et al. (2012faph.confE..20V)
24 = Jakob et al. (2007A&A...461..999J 2007A&A...461..999J)
25 = Faundez et al. (2004A&A...426...97F 2004A&A...426...97F)
26 = Hatchell & van der Tak (2003A&A...409..589H 2003A&A...409..589H)
27 = Sandell (2000A&A...358..242S 2000A&A...358..242S)
28 = Sandell & Sievers (2004ApJ...600..269S 2004ApJ...600..269S)
29 = van der Tak et al. (1999ApJ...522..991V 1999ApJ...522..991V)
30 = Ladd et al. (1993ApJ...419..186L 1993ApJ...419..186L)
31 = van der Tak (2012RSPTA.370.5186V 2012RSPTA.370.5186V)
32 = Matuszak et al. (2015A&A...578A..20M 2015A&A...578A..20M)
33 = Karska et al. (2014A&A...562A..45K 2014A&A...562A..45K)
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Acknowledgements:
Ngan Le, nganle191919(at)gmail.com
(End) Patricia Vannier [CDS] 19-Apr-2023