J/AJ/164/201 Accretion in 9 Orion OB1b T-Tauri stars (Pittman+, 2022)
Towards a Comprehensive View of Accretion, Inner Disks, and Extinction in
Classical T Tauri Stars; An ODYSSEUS Study of the Orion OB1b Association.
Pittman C.V., Espaillat C.C., Robinson C.E., Thanathibodee T., Calvet N.,
Wendeborn J., Hernandez J., Manara C.F., Walter F., Abraham P., Alcala J.M.,
Alencar S.H.P., Arulanantham N., Cabrit S., Eisloffel J., Fiorellino E.,
France K., Gangi M., Grankin K., Herczeg G.J., Kospal A., Mendigutia I.,
Serna J., Venuti L.
<Astron. J., 164, 201 (2022)>
=2022AJ....164..201P 2022AJ....164..201P
ADC_Keywords: Associations, stellar; Stars, pre-main sequence; Accretion;
Spectra, ultraviolet; Spectra, optical; Spectra, infrared
Keywords: Pre-main sequence stars ; Stellar accretion ; Stellar accretion
disks ; Protoplanetary disks ; Reddening law ; Interstellar
extinction ; Hubble Space Telescope ; Very Large Telescope
Abstract:
The coevolution of T-Tauri stars and their surrounding protoplanetary
disks dictates the timescales of planet formation. In this paper, we
present magnetospheric accretion and inner disk wall model fits to
near-UV (NUV) to near-IR (NIR) spectra of nine classical T-Tauri stars
in Orion OB1b as part of the Outflows and Disks around Young Stars:
Synergies for the Exploration of ULLYSES Spectra (ODYSSEUS) survey.
Using NUV-optical spectra from the Hubble UV Legacy Library of Young
Stars as Essential Standards (ULLYSES) Director's Discretionary
Program and optical-NIR spectra from the PENELLOPE VLT Large
Programme, we find that the accretion rates of these targets are
relatively high for the region's intermediate age of 5.0Myr; rates are
in the range of (0.5-17.2)x10-8M☉/yr, with a median value of
1.2x10-8M☉/yr. The NIR excesses can be fit with 1200-1800K inner
disk walls located at 0.05-0.10au from the host stars. We discuss the
significance of the choice in extinction law, as the measured
accretion rate depends strongly on the adopted extinction value. This
analysis will be extended to the complete sample of T-Tauri stars
being observed through ULLYSES to characterize accretion and inner
disks in star-forming regions of different ages and stellar
populations.
Description:
The Hubble UV Legacy Library of Young Stars as Essential Standards
(ULLYSES) program began observations with a sample of eight
coevolution of T-Tauri stars (CTTSs) in the Orion OB1b subassociation
and two weak-lined TTSs (WTTSs; non-accreting sources) in the 25 Ori
cluster. Each target was observed with both Hubble Space Telescope
(HST) and the Very Large Telescope (VLT) contemporaneously.
Objects:
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RA (ICRS) DE Designation(s)
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05 34 00.00 -01 30 00.0 Orion OB1b = Ass Ori OB 1b
05 24 44.82 +01 50 47.2 25 Ori = * 25 Ori
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 176 9 Best-fit accretion shock model parameters of
Orion OB1 CTTS
table4.dat 40 9 Periods and inclinations of Orion OB1 CTTS
table7.dat 42 9 Accretion column temperatures
table8.dat 95 9 Accretion column mass flux rates
fig1.dat 62 9 Model parameters for the 9 sources
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See also:
II/362 : I-band variability of YSOs (Sergison+, 2020)
J/ApJS/101/117 : UBVRIJHKLMNQ photometry in Taurus-Auriga (Kenyon+ 1995)
J/AJ/129/907 : New Ori OB1 members (Briceno+, 2005)
J/ApJ/756/171 : HST far-UV survey H2 emission of T Tau stars (France+, 2012)
J/A+A/551/A107 : X-shooter spectra of 24 young stellar objects (Manara+, 2013)
J/ApJS/208/9 : Intrinsic colors and temperatures of PMS stars (Pecaut+, 2013)
J/A+A/570/A82 : Mapping accretion variability in NGC 2264 (Venuti+, 2014)
J/A+A/600/A20 : Lupus YSOs X-shooter spectroscopy (Alcala+, 2017)
J/A+A/605/A86 : Pre-main sequence stars VLT/X-Shooter spectra (Manara+, 2017)
J/A+A/599/A23 : Accretion-rotation connection in NGC 2264 (Venuti+, 2017)
J/AJ/157/85 : The CIDA Variability Survey of Orion OB1. II. (Briceno+, 2019)
J/AJ/157/196 : Close companions around young stars (Kounkel+, 2019)
J/AJ/160/268 : Infrared photometry of binaries Orion OB1 (Tokovinin+, 2020)
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 9 A9 --- ID Object identifier
11- 14 F4.2 mag AV [0.05/1.44] V band extinction
16- 19 F4.2 mag E_AV [0.02/0.05] Upper uncertainty in AV
21- 24 F4.2 mag e_AV [0.02/0.4] Lower uncertainty in AV
26- 29 F4.2 Rsun Rad [0.84/3.26] Stellar radius
31- 34 F4.2 Rsun E_Rad [0.07/0.4] Upper uncertainty in Rad
36- 39 F4.2 Rsun e_Rad [0.07/0.4] Lower uncertainty in Rad
41- 44 F4.2 Lsun Lum [0.12/1.18] Stellar luminosity
46- 49 F4.2 Lsun e_Lum [0.03/0.3] Uncertainty in Lum
51- 56 F6.4 Lsun Lacc [0.06/0.61] Accretion luminosity
58- 63 F6.4 Lsun E_Lacc [0.00/0.04] Upper uncertainty in Lacc
65- 70 F6.4 Lsun e_Lacc [0.00/0.23] Lower uncertainty in Lacc
72- 77 F6.3 10-8Msun/yr dMass [0.53/17.2] Accretion rate
79- 83 F5.3 10-8Msun/yr E_dMass [0.01/1] Upper uncertainty in dMass
85- 89 F5.3 10-8Msun/yr e_dMass [0.01/7] Lower uncertainty in dMass
91- 97 F7.5 --- f1E10 [0.0001/0.24] 1e10 accretion column
stellar surface fraction covered
99-104 F6.4 --- E_f1E10 [0.0004/0.02] Upper uncertainty in f1E10
106-112 F7.5 --- e_f1E10 [7e-05/0.03] Lower uncertainty in f1E10
114-120 F7.5 --- f1E11 [9e-05/0.02] 1e11 accretion column
stellar surface fraction covered
122-128 F7.5 --- E_f1E11 [0.0001/0.03] Upper uncertainty in f1E11
130-136 F7.5 --- e_f1E11 [3e-05/0.003] Lower uncertainty in f1E11
138-146 F9.7 --- f1E12 [4e-05/0.03] 1e12 accretion column
stellar surface fraction covered
148-155 F8.6 --- E_f1E12 [7e-06/0.002] Upper uncertainty in f1E12
157-165 F9.7 --- e_f1E12 [2e-06/0.01] Lower uncertainty in f1E12
167-171 I5 K Tshock [4800/10542] Shock temperature
173-176 I4 K e_Tshock [14/1910] Uncertainty in Tshock
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 9 A9 --- ID Object identifier
11- 14 F4.1 km/s vsini [3.2/18.4] Projected rotational velocity
16- 18 F3.1 km/s e_vsini [0.8/2] Uncertainty in vsini
20- 22 F3.1 d Per [4.3/7.1] Period
24- 27 F4.1 km/s Vel [8.3/23.5] Stellar rotational velocity
29- 31 F3.1 km/s e_Vel [0.5/2] Uncertainty in Vel
33- 36 F4.1 deg i [9.3/52.4]? Inclination
38- 40 F3.1 deg e_i [2/8]? Uncertainty in i
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Byte-by-byte Description of file: table7.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 9 A9 --- ID Object identifier
11- 14 I4 K T1E10 [3938/4675] 1e10 accretion column temperature
16- 16 I1 K e_T1E10 [1/2] Uncertainty in T1E10
18- 21 I4 K T1E11 [6310/6880] 1e11 accretion column temperature
23- 23 I1 K e_T1E11 [1/3] Uncertainty in T1E11
25- 29 I5 K T1E12 [10679/10973] 1e12 accretion column temperature
31- 31 I1 K e_T1E12 [2/3] Uncertainty in T1E12
33- 37 I5 K Tshock [4800/10542] Weighted-average shock temperature
39- 42 I4 K e_Tshock [14/1910] Uncertainty in Tshock (1)
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Note (1): The error on Tshock comes from the propagated accretion column
temperature and filling factor uncertainties. Since the filling
factor uncertainties are not symmetric, the larger of the two
uncertainties is used in the error propagation.
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Byte-by-byte Description of file: table8.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 9 A9 --- ID Object identifier
11-14 F4.2 --- Mass/Rad [0.08/0.77] Ratio of stellar mass to radius
16-21 F6.4 10-8Msun/yr dM1E10 [0.0007/1] 1010 accretion column model
accretion rate
23-28 F6.4 10-8Msun/yr E_dM1E10 [0.002/0.3] Upper uncertainty in Mdot1E10
30-35 F6.4 10-8Msun/yr e_dM1E10 [0.0004/0.4] Lower uncertainty in Mdot1E10
37-42 F6.4 10-8Msun/yr dM1E11 [0.001/2.1] 1011 accretion column model
accretion rate
44-48 F5.3 10-8Msun/yr E_dM1E11 [0.01/0.7] Upper uncertainty in Mdot1E11
50-55 F6.4 10-8Msun/yr e_dM1E11 [0.001/0.6] Lower uncertainty in Mdot1E11
57-63 F7.4 10-8Msun/yr dM1E12 [0.025/15.1] 1012 accretion column model
accretion rate
65-69 F5.3 10-8Msun/yr E_dM1E12 [0.004/2] Upper uncertainty in Mdot1E12
71-76 F6.4 10-8Msun/yr e_dM1E12 [0.001/5] Lower uncertainty in Mdot1E12
78-83 F6.3 10-8Msun/yr dMTot [0.529/17.2] Total accretion rate
85-89 F5.3 10-8Msun/yr E_dMTot [0.018/1.0] Upper uncertainty in MdotTot
91-95 F5.3 10-8Msun/yr e_dMTot [0.016/4.0] Lower uncertainty in MdotTot
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Byte-by-byte Description of file: fig1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 9 A9 --- ID Object identifier
11-14 F4.2 mag AV [0.05/1.43] V band extinction
16-19 F4.2 Rsun Rad [0.84/3.26] Stellar radius
21-29 F9.6 10-8Msun/yr dMass [0.52/17.3] Accretion rate
31-38 F8.6 --- f1E10 [4e-5/0.24] 1e10 accretion column stellar
surface fraction covered
40-47 F8.6 --- f1E11 [4e-5/0.02] 1e11 accretion column stellar
surface fraction covered
49-56 F8.6 --- f1E12 [4e-5/0.03] 1e12 accretion column stellar
surface fraction covered
58-62 I5 K Tshock [4802/10650] Weighted-average shock temperature
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Nomenclature Notes:
History:
From electronic version of the journal
(End) Prepared by [AAS], Coralie Fix [CDS], 17-Jan-2023