J/AJ/157/159 Stellar parameters for 131 Herbig Ae/Be stars (Arun+, 2019)
On the mass accretion rate and infrared excess in Herbig Ae/Be stars.
Arun R., Mathew B., Manoj P., Ujjwal K., Kartha S.S., Viswanath G.,
Narang M., Paul K.T.
<Astron. J., 157, 159 (2019)>
=2019AJ....157..159A 2019AJ....157..159A (SIMBAD/NED BibCode)
ADC_Keywords: Stars, pre-main sequence ; Stars, Be ; Stars, distances ;
Stars, ages ; Stars, masses
Keywords: accretion, accretion disks - protoplanetary disks -
stars: emission-line, Be - stars: pre-main sequence -
stars: variables: T Tauri, Herbig Ae/Be
Abstract:
The present study makes use of the unprecedented capability of the Gaia
mission to obtain the stellar parameters such as distance, age, and mass
of HAeBe stars. The accuracy of Gaia DR2 (Cat. I/345) astrometry is
demonstrated from the comparison of the Gaia DR2 distances of 131 HAeBe
stars with the previously estimated values from the literature. This
is one of the initial studies to estimate the age and mass of a confirmed
sample of HAeBe stars using both the photometry and distance from the Gaia
mission. Mass accretion rates are calculated from Hα line flux
measurements of 106 HAeBe stars. Since we used distances and the stellar
masses derived from the Gaia DR2 data in the calculation of the mass
accretion rate, our estimates are more accurate than previous studies.
The mass accretion rate is found to decay exponentially with age, from
which we estimated a disk dissipation timescale of 1.9±0.1 Myr. The mass
accretion rate and stellar mass exhibit a power-law relation of the form
Macc∝M*2.8±0.2. From the distinct distribution in the
values of the infrared spectral index, n2-4.6, we suggest the possibility
of difference in the disk structure between Herbig Be and Herbig Ae stars.
Description:
A sample of 142 stars is taken from Mathew et al. (2018ApJ...857...30M 2018ApJ...857...30M),
which is a carefully selected, well-studied sample of HAeBe stars from
The et al. (1994 ,J/A+AS/104/315), Manoj et al. (2006, J/ApJ/653/657),
and Fairlamb et al. (2015, J/MNRAS/453/976). The coordinates, proper
motions, and V magnitudes of the 142 stars are taken from the literature.
R.A. and decl. of these stars are converted from J2000 to J2015.5 epoch
using their proper motion. A query for a Gaia DR2 match for these stars
was then performed around the converted coordinates with a search radius
of 10 arcsec via the Mikulski Archive for Space Telescopes
(http://archive.stsci.edu/). If a match was not found, then the search
radius was increased up to 30 arcsec. This procedure returned 354 Gaia DR2
rows for 142 stars. For 60 stars, only one Gaia DR2 match was returned.
For the remaining 82 stars with multiple entries, those which had
|G-V| mag>3.5 were removed. For the remaining multiple entries, the
Gaia DR2 row with the closest positional match was selected for which
|G-V| mag=<2. Thus we got the Gaia DR2 parallax and magnitudes for all
stars in the sample. After avoiding 11 sources, where 6 showed no parallax
data and 5 had negative parallax, we finalized our sample of HAeBe stars
to be 131. These stars are found in the distance range of 0.09-6 kpc,
with a range in Gaia G-band magnitude from 4.4 to 14.5 mag.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 107 131 Stellar parameters for our sample of 131 HAeBe
stars
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See also:
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
J/A+AS/104/315 : Member of Herbig Ae/Be stellar group (The+ 1994)
J/AJ/118/1043 : Herbig Ae/Be stars catalog (Herbst+, 1999)
J/AJ/126/2971 : UBVRI photometry of 131 Herbig Ae/Be (Vieira+, 2003)
J/ApJ/653/657 : Spectroscopic observations of Herbig Ae/Be stars
(Manoj+, 2006)
J/MNRAS/453/976 : Herbig Ae/Be X-shooter observations (Fairlamb+, 2015)
J/other/NewA/44.1 : Infrared photometric study of Herbig Ae/Be stars
(Chen+, 2016)
J/A+A/620/A128 : Gaia DR2 study of Herbig Ae/Be stars (Vioque+, 2018)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 15 A15 --- ID Object identifier
17- 20 I4 pc Dist [96/5905] Distance
22- 25 I4 pc E_Dist [0/2141] Upper uncertainty in Dist
27- 30 I4 pc e_Dist [0/1256] Lower uncertainty in Dist
32 A1 --- l_Age [<] Limit flag on Age
33- 37 F5.2 Myr Age [0.1/14.1]? Age from this work
39- 42 F4.2 Myr E_Age [0.01/2.91]? Upper uncertainty in Age
44- 47 F4.2 Myr e_Age [0.01/2.41]? Lower uncertainty in Age
49- 54 F6.3 Myr Age-V18 [0.011/18.5]? Age from Vioque et al. (2018,
J/A+A/620/A128)
56- 61 F6.3 Myr E_Age-V18 [0.006/18]? Upper uncertainty in Age-V18
63- 67 F5.3 Myr e_Age-V18 [0.001/5]? Lower uncertainty in Age-V18
68 A1 --- f_Age-V18 [*] Flag on Age-V18 (1)
70 A1 --- l_Mass [>] Limit flag on Mass
71- 76 F6.2 Msun Mass [1.49/25]? Mass from this work
78- 81 F4.2 Msun E_Mass [0.01/1.35]? Upper uncertainty in Mass
83- 86 F4.2 Msun e_Mass [0.01/0.94]? Lower uncertainty in Mass
88- 93 F6.3 Msun Mass-V18 [1.21/31.2]? Mass from Vioque et al. (2018,
J/A+A/620/A128)
95-100 F6.3 Msun E_Mass-V18 [0.061/11]? Upper uncertainty in V18-Mass
102-106 F5.3 Msun e_Mass-V18 [0.061/7]? Lower uncertainty in V18-Mass
107 A1 --- f_Mass-V18 [*] Flag on Mass-V18 (1)
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Note (1): Flag as follows:
* = The errors in our age and mass estimates are rounded off to two digits
whereas those from Vioque et al. (2018, J/A+A/620/A128) is reproduced
as in their paper.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Tiphaine Pouvreau [CDS] 17-Jul-2019