J/A+A/602/A33 X-Shooter spectroscopy of YSOs in Lupus (Frasca+, 2017)
X-Shooter spectroscopy of young stellar objects in Lupus.
Atmospheric parameters, membership and activity diagnostics.
Frasca A., Biazzo K., Alcala J.M., Manara C.F., Stelzer B., Covino E.,
Antoniucci S.
<Astron. Astrophys. 602, A33 (2017)>
=2017A&A...602A..33F 2017A&A...602A..33F (SIMBAD/NED BibCode)
ADC_Keywords: Stars, pre-main sequence ; YSOs ; Spectroscopy ;
Effective temperatures ; Radial velocities ; Rotational velocities
Keywords: stars: pre-main sequence - stars: fundamental parameters -
stars: chromospheres - accretion, accretion disks -
open clusters and associations: individual: Lupus
Abstract:
A homogeneous determination of basic stellar parameters of young
stellar object (YSO) candidates is needed to confirm their pre-main
sequence evolutionary stage, membership to star forming regions
(SFRs), and to get reliable values of the quantities related to
chromospheric activity and accretion.
We used the code ROTFIT and synthetic BT-Settl spectra for the
determination of the atmospheric parameters (Teff and logg), the
veiling (r), the radial (RV) and projected rotational velocity
(vsini), from X-Shooter spectra of 102 YSO candidates (95 of infrared
Class II and seven Class III) in the Lupus SFR.
The spectral subtraction of inactive templates, rotationally broadened
to match the vsini of the targets, enabled us to measure the line
fluxes for several diagnostics of both chromospheric activity and
accretion, such as Hα, Hβ, CaII, and NaI lines.
We have shown that 13 candidates can be rejected as Lupus members
based on their discrepant RV with respect to Lupus and/or the very low
logg values. At least 11 of them are background giants, two of which
turned out to be lithium-rich giants. Regarding the members, we found
that all ClassIII sources have Hα fluxes compatible with a pure
chromospheric activity, while objects with disks lie mostly above the
boundary between chromospheres and accretion. YSOs with transitional
disks displays both high and low Hα fluxes. We found that the
line fluxes per unit surface are tightly correlated with the accretion
luminosity (Lacc) derived from the Balmer continuum excess. This
rules out that the relationships between Lacc and line luminosities
found in previous works are simply due to calibration effects. We also
found that the CaII-IRT flux ratio is always small, indicating an
optically thick emission source. The latter can be identified with the
accretion shock near the stellar photosphere. The Balmer decrement
reaches instead, for several accretors, high values typical of
optically thin emission, suggesting that the Balmer emission
originates in different parts of the accretion funnels with a smaller
optical depth.
Description:
Membership, atmospheric parameters (Teff, logg, and [Fe/H]), radial
velocity (RV), projected rotational velocity (vsini) and veiling at
five wavelengths are listed for 102 Lupus YSO candidates in Table 1.
Mass and age are also reported in Table 1 for the members, with the
exception of subluminous sources.
Table 2 reports the full width at 10% maximum of the Hα line and
the fluxes in the Hα, Hβ, CaII-IRT, CaII-K, and NaI,D1,2
lines.
Table 3 reports the fluxes for Paγ, Paβ, and Brγ
measured in the NIR X-Shooter spectra.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 145 102 Stellar Parameters
table2.dat 209 89 Hα, Hβ, CaII, and NaI fluxes
table3.dat 103 89 Paγ, Paβ, and Brγ fluxes
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See also:
J/ApJ/658/480 : Pre-main-sequence stars in Lupus association (Makarov+, 2007)
J/ApJS/177/551 : Spitzer c2d survey of Lupus dark clouds (Merin+, 2008)
J/ApJS/181/321 : Properties of Spitzer c2d dark clouds (Evans+, 2009)
J/A+A/580/A26 : T Tauri star population in Lupus (Galli+, 2015)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 22 A22 --- Name Name
24- 25 I2 h RAh Right ascension (J2000)
27- 28 I2 min RAm Right ascension (J2000)
30- 34 F5.2 s RAs Right ascension (J2000)
36 A1 --- DE- Declination sign (J2000)
37- 38 I2 deg DEd Declination (J2000)
40- 41 I2 arcmin DEm Declination (J2000)
43- 46 F4.1 arcsec DEs Declination (J2000)
48- 57 F10.4 d HJD Reduced Heliocentric Julian day (HJD-2400000)
59 A1 --- fMemb [Y/N] Membership flag (1)
61- 63 A3 --- Class ?=- Classification based on the SED
65- 68 I4 K Teff Effective temperature
70- 72 I3 K e_Teff Effective temperature error
74- 77 F4.2 [cm/s2] logg ?=- Logarithm of surface gravity
79- 82 F4.2 [cm/s2] e_logg ?=- Error on logarithm of surface gravity
84 A1 --- l_vsini Limit flag on vsini
85- 89 F5.1 km/s vsini ?=- Projected rotational velocity
91- 95 F5.1 km/s e_vsini ?=- Projected rotational velocity error
97-102 F6.1 km/s HRV Heliocentric Radial Velocity
104-107 F4.1 km/s e_HRV Heliocentric Radial Velocity error
109 A1 --- l_r970 Limit flag on veiling at 970nm
110-112 F3.1 --- r970 ?=- Veiling at 970nm
114 A1 --- l_r710 Limit flag on veiling at 710nm
115-117 F3.1 --- r710 ?=- Veiling at 710nm
119 A1 --- l_r620 Limit flag on veiling at 620nm
120-122 F3.1 --- r620 ?=- Veiling at 620nm
124 A1 --- l_r540 Limit flag on veiling at 540nm
125-127 F3.1 --- r540 ?=- Veiling at 540nm
129 A1 --- l_r450 Limit flag on veiling at 450nm
130-132 F3.1 --- r450 ?=- Veiling at 450nm
134-138 F5.3 Msun Mass ?=- Stellar mass
140-143 F4.1 Myr Age ?=- Age
145 A1 --- Notes [*abcde] Individual notes (2)
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Note (1): Membership flag as follows:
Y = member
N = non member
Note (2): Notes as follows:
* = Mass and age derived from Siess et al. (2000A&A...358..593S 2000A&A...358..593S)
evolutionary models
a = Subluminous objects
b = Flat IR source (Merin et al., 2008, Cat. J/ApJS/177/551). Subluminous
with the optical luminosity. Mass and age derived adopting the
bolometric luminosity of 0.18L☉
(Evans et al., 2009, Cat. J/ApJS/181/321)
c = Originally selected as ClassII
d = Originally selected as ClassIII
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 22 A22 --- Name Name
24- 25 I2 h RAh Right ascension (J2000)
27- 28 I2 min RAm Right ascension (J2000)
30- 34 F5.2 s RAs Right ascension (J2000)
36 A1 --- DE- Declination sign (J2000)
37- 38 I2 deg DEd Declination (J2000)
40- 41 I2 arcmin DEm Declination (J2000)
43- 46 F4.1 arcsec DEs Declination (J2000)
48- 52 F5.1 km/s W10Ha ?=- Hα full width at 10% of the peak
level
54- 57 F4.1 km/s e_W10Ha ?=- Error of W10Ha
59 A1 --- l_FHa Limit flag on Hα flux
60- 67 E8.2 mW/m2 FHa ?=- Hα flux
69- 76 E8.2 mW/m2 e_FHa ?=- Hα flux error
78 A1 --- l_FHb Limit flag on Hβ flux
79- 86 E8.2 mW/m2 FHb ?=- Hβ flux
88- 95 E8.2 mW/m2 e_FHb ?=- Hβ flux error
97 A1 --- l_F8498 Limit flag on CaII-8498 flux
98-105 E8.2 mW/m2 F8498 ?=- CaII-8498 flux
107-114 E8.2 mW/m2 e_F8498 ?=- CaII-8498 flux error
116 A1 --- l_F8542 Limit flag on CaII-8542 flux
117-124 E8.2 mW/m2 F8542 ?=- CaII-8542 flux
126-133 E8.2 mW/m2 e_F8542 ?=- CaII-8542 flux error
135 A1 --- l_F8662 Limit flag on CaII-8662 flux
136-143 E8.2 mW/m2 F8662 ?=- CaII-8662 flux
145-152 E8.2 mW/m2 e_F8662 ?=- CaII-8662 flux error
154 A1 --- l_FCaII-K Limit flag on CaII-K flux
155-162 E8.2 mW/m2 FCaII-K ?=- CaII-K flux
164-171 E8.2 mW/m2 e_FCaII-K ?=- CaII-K flux error
173 A1 --- l_FNa5890 Limit flag on NaI-5890 flux
174-181 E8.2 mW/m2 FNa5890 ?=- NaI-5890 flux
183-190 E8.2 mW/m2 e_FNa5890 ?=- NaI-5890 flux error
192 A1 --- l_FNa5896 Limit flag on NaI-5896 flux
193-200 E8.2 mW/m2 FNa5896 ?=- NaI-5896 flux
202-209 E8.2 mW/m2 e_FNa5896 ?=- NaI-5896 flux error
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 22 A22 --- Name Name
24- 25 I2 h RAh Right ascension (J2000)
27- 28 I2 min RAm Right ascension (J2000)
30- 34 F5.2 s RAs Right ascension (J2000)
36 A1 --- DE- Declination sign (J2000)
37- 38 I2 deg DEd Declination (J2000)
40- 41 I2 arcmin DEm Declination (J2000)
43- 46 F4.1 arcsec DEs Declination (J2000)
48 A1 --- l_FPa-g Limit flag on Pa-γ flux
49- 56 E8.2 mW/m2 FPa-g ?=- Paschen-γ flux
58- 65 E8.2 mW/m2 e_FPa-g ?=- Paschen-γ flux error
67 A1 --- l_FPa-b Limit flag on Pa-β flux
68- 75 E8.2 mW/m2 FPa-b ?=- Paschen-β flux
77- 84 E8.2 mW/m2 e_FPa-b ?=- Paschen-β flux error
86 A1 --- l_FBr-g Limit flag on Brackett-γ flux
87- 94 E8.2 mW/m2 FBr-g ?=- Brackett-γ flux
96-103 E8.2 mW/m2 e_FBr-g ?=- Brackett-γ flux error
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Acknowledgements:
Antonio Frasca, antonio.frasca(at)oact.inaf.it
(End) Antonio Frasca [INAF-OACt, Italy], Patricia Vannier [CDS] 24-Mar-2017