J/A+A/675/A204 Properties of PMS stars in NGC 299 (Vlasblom+, 2023)
Photometric determination of the mass accretion rates of pre-main-sequence
stars. VIII. Recent star formation in NGC 299
Vlasblom M., De Marchi G.
<Astron. Astrophys. 675, A204 (2023)>
=2023A&A...675A.204V 2023A&A...675A.204V (SIMBAD/NED BibCode)
ADC_Keywords: Magellanic Clouds ; Stars, pre-main sequence ; Photometry, HST ;
Photometry, H-alpha
Keywords: stars: formation - stars: pre-main-sequence
Magellanic Clouds - galaxies: star clusters: individual: NGC 299 -
open clusters and associations: individual: NGC 299
Abstract:
We studied the properties of the young stellar populations in the NGC
299 cluster in the Small Magellanic Cloud using observations obtained
with the Hubble Space Telescope in the V, I, and Hα bands. We
identified 250 stars with Hα excess exceeding 5 sigma and an
equivalent width of the Hα emission line of at least 20Å,
which indicates that these stars are still undergoing active accretion
and therefore represent bona fide pre-main-sequence (PMS) objects. For
240 of them, we derived physical stellar parameters such as the mass,
age, and mass accretion rate by comparing the observed photometry with
theoretical models. We find evidence that suggests the existence of
two populations of PMS stars, one with a median age of around 25Myr
and the other about 50Myr old. These ages are consistent with
previously determined ages for the main population of the cluster. The
average mass accretion rate for these PMS stars is roughly 5e-9
Msun/yr, which is comparable to the values found with the same method
in other low-metallicity, low-density clusters in the Magellanic
Clouds, but is about a factor of three lower than those measured for
stars of similar mass and age in denser Magellanic Cloud stellar
regions. Our findings support the hypothesis that both the metallicity
and density of the forming environment can affect the mass accretion
rate and thus the star formation process in a region.
Description:
Photometry of the 7929 stars detected in NGC 299, as well as the
derived parameters of the 240 PMS stars are presented. For the full
sample of stars, the position, V, I and Hα magnitudes, and the
uncertainty on these magnitudes are given. For the PMS stars, the
effective temperature, bolometric luminosity, radius, mass age, age
uncertainty, Hα luminosity and mass accretion rate are also
given.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 65 7929 Position, magnitudes, and uncertainties of
the 7929 selected sources
table3.dat 95 240 Physical parameters of the 240 bona fide
PMS stars
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See also:
J/ApJ/875/51 : Mass accretion rates of PMS stars. VI. LH95 in LMC
(Biazzo+, 2019)
J/A+A/675/A203 : NGC 376 photometric catalogue (Tsilia+, 2023)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 4 I4 --- ID Identification number for this catalogue
6- 7 I2 h RAh Right Ascension (J2000)
9- 10 I2 min RAm Right Ascension (J2000)
12- 18 F7.4 s RAs Right Ascension (J2000)
20 A1 --- DE- Declination sign (J2000)
21- 22 I2 deg DEd Declination (J2000)
24- 25 I2 arcmin DEm Declination (J2000)
27- 32 F6.3 arcsec DEs Declination (J2000)
34- 38 F5.2 mag Imag I band magnitude
40- 43 F4.2 mag e_Imag Uncertainty on I band magnitude
45- 49 F5.2 mag Vmag V band magnitude
51- 54 F4.2 mag e_Vmag Uncertainty on V band magnitude
56- 60 F5.2 mag Hamag Hα band magnitude
62- 65 F4.2 mag e_Hamag Uncertainty on Hα band magnitude
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 I4 --- ID Identification number for this catalogue
6- 7 I2 h RAh Right Ascension (J2000)
9- 10 I2 min RAm Right Ascension (J2000)
12- 18 F7.4 s RAs Right Ascension (J2000)
20 A1 --- DE- Declination sign (J2000)
21- 22 I2 deg DEd Declination (J2000)
24- 25 I2 arcmin DEm Declination (J2000)
27- 32 F6.3 arcsec DEs Declination (J2000)
34- 38 F5.2 mag Imag I band magnitude
40- 44 F5.2 mag Vmag V band magnitude
46- 50 F5.2 mag Hamag Hα band magnitude
52- 55 I4 K Teff Effective temperature
57- 63 E7.1 [Lsun] Lbol Bolometric luminosity
65- 68 F4.2 Rsun R Stellar radius
70- 73 F4.2 Msun Mass Stellar mass
75- 78 F4.1 Myr Age ?=0 Stellar age
80- 82 F3.1 Myr e_Age ?=0 Uncertainty on stellar age
84- 90 E7.1 Lsun LHalpha Hα luminosity
92- 95 F4.1 [Msun/yr] logdMacc/dt ?=0 Mass accretion rate
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Acknowledgements:
Marissa Vlasblom, vlasblom(at)strw.leidenuniv.nl
References:
De Marchi et al., Paper I 2010ApJ...715....1D 2010ApJ...715....1D
De Marchi et al., Paper II 2011ApJ...740...11D 2011ApJ...740...11D
De Marchi et al., Paper III 2013ApJ...775...68D 2013ApJ...775...68D
De Marchi et al., Paper IV 2013ApJ...775...68D 2013ApJ...775...68D
De Marchi et al., Paper V 2017ApJ...846..110D 2017ApJ...846..110D
Biazzo et al., Paper VI 2019ApJ...875...51B 2019ApJ...875...51B, Cat. J/ApJ/876/51
Tsilia et al. Paper VII 2023A&A...675A.203T 2023A&A...675A.203T, Cat. J/A+A/675/A203
(End) Patricia Vannier [CDS] 15-May-2023