J/MNRAS/488/2158 Young star clusters 2nd Galactic quadrant (Molina Lera+, 2019)
Young star clusters and the structure of the second Galactic quadrant II.
Molina Lera J.A., Baume G., Gamen R.
<Mon. Not. R. Astron. Soc., 488, 2158-2174 (2019)>
=2019MNRAS.488.2158M 2019MNRAS.488.2158M (SIMBAD/NED BibCode)
ADC_Keywords: Stars, early-type ; Photometry, ugriz ; Positional data ;
Spectral types ; Clusters, open ; Spectra, optical
Keywords: stars: early-type - stars: formation -
open clusters and associations: general - Galaxy: structure
Abstract:
Galactic spiral arms are traced using young objects as giant molecular
clouds, HII regions, OB stars, or young open/embedded clusters. To
improve the knowledge of the Galactic structure in the second quadrant
we selected, from more than 200 open clusters covered by the SDSS, a
sample of 10 young stellar clusters to conduct a spectrophotometric
study.
Photometric data were provided by SDSS and APASS in the optic bands
and by 2MASS and WISE in the infrared. Spectroscopic information was
obtained from observations acquired with GMOS/GEMINI complemented with
data from the literature. For six of the 10 clusters, distances were
also obtained with our astrometric Gaia data analysis. To perform all
tasks we used a suite of tools developed by us.
Our results show that these open clusters are distributed along three
spiral arms, covering distances from 1.8 to 8.0kpc. We confirm, using
our novel spectroscopic data, our previews photometric estimations
regarding the Galactic location of the cluster Teutsch 45. We found
that it is located beyond the 'Outer Arm' and probably belong to the
more distant 'New Arm' extending its trace almost to the anticentre.
Hence, it was possible to get a better picture of the structure of the
outer regions of the Galaxy. For clusters with pre-main-sequence
populations we also found traces of coeval star formation processes.
Regarding spectroscopic data and most massive members of the clusters,
we discovered seven B-type stars, all earlier than B4 and we also
confirmed the spectral classification of one O8-8.5 type star.
Description:
We used photometry at ugri bands provided by the SDSS-III data release
(http://www.sdss3.org/). This catalogue was compiled from observations
made in a dedicated 2.5m f/5 telescope at Apache Point Observatory.
However, this catalogue lacks photometric information of the objects
located around very bright stars, crowded regions, and several star
clusters beside if they are crowded or not. Saturated stars were
complemented, when available, with gri data from the APASS Data
Release 9 (Henden et al. 2015AAS...22533616H, Cat. II/336) catalogue
for most cases, and for a few stars we used SIMBAD data base.
Spectroscopic information of the stars in the clusters were searched
in the SIMBAD data base (http://simbad.u-strasbg.fr/simbad/). Since
several clusters lacked of such information we obtained new
spectroscopic data using poor weather time at Gemini North. Based on
our preliminary photometric analysis, we selected some objects with
high probability to be early-type stars, and observe them with the
Gemini Multi-Object Spectrograph (GMOS
http://www.gemini.edu/sciops/instruments/gmos/) during nights of 2018
December (proposal ID: GN-2018B-Q-408; PI: JAML).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 32 40 Photometric zero-point and rms values for each
studied cluster region
table2.dat 97 10 Fundamental parameters of the studied star
clusters
table3.dat 94 49 Main parameters for stars with spectral type
phbd2003.dat 107 6602 Photometry of [BDS2003] 39 stars
phbfs16.dat 107 8219 Photometry of BFS 16 stars
phfsr417.dat 107 9076 Photometry of FSR 0417 stars
phiras23.dat 107 4195 Photometry of IRAS 23151+5912 stars
phkron80.dat 107 4840 Photometry of Kronberger 80 stars
phngc654.dat 107 6272 Photometry of NGC 654 stars
phngc659.dat 107 9479 Photometry of NGC 659 stars
phngc751.dat 107 8553 Photometry of NGC 7510 stars
phteut45.dat 107 3943 Photometry of Teutsch 45 stars
phwater1.dat 107 2687 Photometry of Waterloo 1 stars
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See also:
V/147 : The SDSS Photometric Catalogue, Release 12 (Alam+, 2015)
II/336 : AAVSO Photometric All Sky Survey (APASS) DR9 (Henden+, 2016)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 15 A15 --- Name Cluster name
17 A1 --- Band [ugri] Observed band
19- 22 F4.2 --- zp Zero-point correction from fit
24- 27 F4.2 --- e_zp Error on zp
29- 32 F4.2 --- rms Root mean square value from fit
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 15 A15 --- Name Cluster name
17- 18 I2 h RAh Right ascension (J2000)
20- 21 I2 min RAm Right ascension (J2000)
23- 26 F4.1 s RAs Right ascension (J2000)
28 A1 --- DE- Declination sign (J2000)
29- 30 I2 deg DEd Declination (J2000)
32- 33 I2 arcmin DEm Declination (J2000)
35- 38 F4.1 arcsec DEs Declination (J2000)
40- 43 F4.1 arcmin Radius Cluster radius
45- 47 F3.1 --- rho0/out Ratio between the peak density value and a
representative one of the field density
49- 52 F4.2 mag E(B-V) E(B-V) colour excess
54- 57 F4.2 mag delta Shifting value adopted taking into account
the differential reddening and/or possible
evolution effects
59- 62 F4.1 --- V0-MV Dereddened minus absolute V magnitude
(distance modulus)
64 A1 --- l_Agenuc [~] Limit flag on Agenuc
66- 67 I2 Myr Agenuc ? Nuclear age
69- 70 I2 Myr b_Agenuc []? Lower bound on Agenuc
72- 73 I2 Myr B_Agenuc []? Upper bound on Agenuc
75 A1 --- l_Agecon [~] Limit flag on Agecon
77- 78 I2 Myr Agecon ? Contraction age
80- 81 I2 Myr b_Agecon []? Lower bound on Agecon
83- 84 I2 Myr B_Agecon []? Upper bound on Agecon
86- 97 A12 --- FileName Name of the table with photometry of
cluster stars
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 15 A15 --- Name Cluster name
17- 18 A2 --- r_OName Reference on OName (1)
20 A1 --- f_OName [*] Flag on OName (2)
22- 38 A17 --- OName Alternative name from 2MASS or other ID
(JHHMMSSss+DDMMSSs or HHMMSSss+DDMMSSs)
40- 41 I2 h RAh Right ascension (J2000)
43- 44 I2 min RAm Right ascension (J2000)
46- 49 F4.1 s RAs Right ascension (J2000)
51 A1 --- DE- Declination sign (J2000)
52- 53 I2 deg DEd Declination (J2000)
55- 56 I2 arcmin DEm Declination (J2000)
58- 61 F4.1 arcsec DEs Declination (J2000)
63- 69 A7 --- SpType Spectral type
71- 77 A7 --- SpTypead Adopted spectral type
79- 83 F5.2 mag VMAG Absolute V magnitude
85- 88 F4.2 mag E(B-V) ? E(B-V) colour excess
90- 94 F5.2 mag V0-MV ? Dereddened minus absolute V magnitude
(distance modulus)
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Note (1): References as follows:
TW = This work
SB = SIMBAD (http://simbad.u-strasbg.fr/simbad/)
MS = Mathew & Subramaniam (2011BASI...39..517M 2011BASI...39..517M, Cat. J/other/BASI/39.517)
R = Russeil et al. (2007A&A...470..161R 2007A&A...470..161R, Cat. J/A+A/470/161)
Note (2): Flag as follows:
* = Star used to estimate clusters parameters
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Byte-by-byte Description of file: ph*
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Bytes Format Units Label Explanations
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1- 4 I4 --- ID Star internal identifier
6- 19 F14.10 deg RAdeg Right ascension (J2000)
21- 33 F13.10 deg DEdeg Declination (J2000)
35- 41 F7.4 mag umag ? SDSS u-band magnitude
43- 47 F5.3 mag e_umag ? Error on umag
49- 55 F7.4 mag gmag ? SDSS g-band magnitude
57- 62 F6.3 mag e_gmag ? Error on gmag
64- 70 F7.4 mag rmag ? SDSS r-band magnitude
72- 77 F6.3 mag e_rmag ? Error on rmag
79- 85 F7.4 mag imag ? SDSS i-band magnitude
87- 92 F6.3 mag e_imag ? Error on imag
94- 99 F6.4 --- chi Reduced chi-squared
101-107 F7.4 --- sharp Sharp parameter
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History:
From electronic version of the journal
References:
Molina et al. Paper I 2018MNRAS.480.2386M 2018MNRAS.480.2386M
(End) Ana Fiallos [CDS] 06-Dec-2022