J/ApJ/841/116 Herschel spectra of 11 very low mass stars (Hendler+, 2017)
Hints for small disks around very low mass stars and brown dwarfs.
Hendler N.P., Mulders G.D., Pascucci I., Greenwood A., Kamp I., Henning T.,
Menard F., Dent W.R.F., Evans II N.J.
<Astrophys. J., 841, 116-116 (2017)>
=2017ApJ...841..116H 2017ApJ...841..116H (SIMBAD/NED BibCode)
ADC_Keywords: Spectra, infrared ; Stars, masses ; Stars, brown dwarf
Keywords: brown dwarfs; circumstellar matter; protoplanetary disks
Abstract:
The properties of disks around brown dwarfs and very low mass stars
(hereafter VLMOs) provide important boundary conditions on the process
of planet formation and inform us about the numbers and masses of
planets than can form in this regime. We use the Herschel Space
Observatory PACS spectrometer to measure the continuum and [OI]63µm
line emission toward 11 VLMOs with known disks in the Taurus and
Chamaeleon I star-forming regions. We fit radiative transfer models to
the spectral energy distributions of these sources. Additionally, we
carry out a grid of radiative transfer models run in a regime that
connects the luminosity of our sources with brighter T Tauri stars. We
find that VLMO disks with sizes 1.3-78au, smaller than typical T Tauri
disks, fit well the spectral energy distributions assuming that disk
geometry and dust properties are stellar mass independent. Reducing
the disk size increases the disk temperature, and we show that VLMOs
do not follow previously derived disk temperature-stellar luminosity
relationships if the disk outer radius scales with stellar mass. Only
2 out of 11 sources are detected in [OI] despite a better sensitivity
than was achieved for T Tauri stars, suggesting that VLMO disks are
underluminous. Using thermochemical models, we show that smaller disks
can lead to the unexpected [OI]63µm nondetections in our sample.
The disk outer radius is an important factor in determining the gas
and dust observables.
Description:
Our sample comprises 11 very low mass stars (VLMOs) and brown dwarfs
from two nearby star-forming regions, Taurus and Chamaeleon I
(d=162pc). Because we use stellar parameters from Rebull+ (2010,
J/ApJS/186/259) for the majority of our Taurus sources, we adopt their
distance of 137pc for the Taurus star-forming region.
Ten of the sources were selected by us and observed in 2013 February
and March with the Herschel/PACS spectrograph as part of Proposal ID
OT2ipascucc2. CIDA-1 is the only other VLMO observed with the same
setting (Proposal ID OT1ascholz1); hence, we include it in our
analysis. Spectra were centered on the [OI]63um line and covered from
62.93 to 63.43um. The red channel observations were a bonus and
covered from 188.77 to 190.35um.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 74 11 Source properties
table3.dat 62 11 Observed continuum flux densities and line fluxes
table4.dat 880 11 Source photometry
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See also:
J/A+A/337/403 : Low-mass stars evolutionary models (Baraffe+ 1998)
J/A+A/416/555 : Brown Dwarfs in ChaI Dark Cloud (Lopez-Marti+ 2004)
J/A+A/446/485 : New very low-mass members in Taurus (Guieu+, 2006)
J/ApJ/645/676 : Spatial distribution of brown dwarfs in Taurus (Luhman+, 2006)
J/ApJ/675/1375 : IRAC/MIPS photometry in Cha I (Luhman+, 2008)
J/ApJ/684/654 : Low-mass members of Chamaeleon I (Luhman+, 2008)
J/ApJS/186/111 : Spitzer observations of Taurus members (Luhman+, 2010)
J/ApJS/186/259 : Taurus Spitzer survey: new candidate members (Rebull+, 2010)
J/ApJ/731/8 : Multiple star formation in Taurus-Auriga (Kraus+, 2011)
J/PASP/125/477 : Gas Survey of Protoplanetary Systems. I. (Dent+, 2013)
J/ApJ/771/129 : Submillimetric Class II sources of Taurus (Andrews+, 2013)
J/ApJ/773/168 : Submm fluxes of very low-mass stars and BDs (Mohanty+, 2013)
J/ApJ/788/40 : Late-type targets in Taurus, ChaI & Upper Sco (Todorov+, 2014)
J/A+A/570/A29 : TBOSS Survey I: Herschel/PACS (Bulger+, 2014)
J/MNRAS/444/1157 : Members of ONC and Tau-Aur (Davies+, 2014)
J/A+A/594/A59 : Far-IR lines in YSOs Herschel-PACS (Riviere-Marichalar+, 2016)
J/ApJ/831/125 : ALMA 887um obs. of ChaI star-forming region (Pascucci+, 2016)
J/AJ/153/46 : Spectroscopy of candidate members in Taurus (Luhman+, 2017)
J/AJ/154/46 : Proper motions & photom. for members of Cha I (Esplin+, 2017)
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 17 A17 --- 2MASS 2MASS name (JHHMMSSss+DDMMSSs)
19- 28 A10 --- Name Common name
30- 35 A6 --- Reg Region (1)
37- 41 A5 --- SpT MK spectral type
43- 45 A3 --- r_SpT Reference (2)
47- 50 F4.2 mag Av [0/4.6] Visual extinction
52 A1 --- f_Av [b] Flag on Av (3)
54- 58 F5.2 [Lsun] logLbol [-2.3/-0.7] Log of bolometric luminosity
60 A1 --- f_logLbol [a] a: GM Tau luminosity from
Davies+ 2014, J/MNRAS/444/1157
62- 64 A3 --- Ref Reference (2)
66- 69 I4 K Teff [2765/3125] Effective temperature
71- 74 F4.2 Msun Mass [0.04/0.2] Mass
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Note (1): A distance of 137 and 162pc is assumed for the Taurus
(Rebull+ 2010, J/ApJS/186/25) and
Chamaeleon I sources (Luhman+ 2007ApJ...666.1219L 2007ApJ...666.1219L).
Note (2): Reference as follows:
D14 = Davies et al. 2014, J/MNRAS/444/1157
H08 = Herczeg & Hillenbrand 2008ApJ...681..594H 2008ApJ...681..594H
L07 = Luhman et al. 2007ApJ...666.1219L 2007ApJ...666.1219L
L09 = Luhman et al. 2009ApJ...703..399L 2009ApJ...703..399L
L17 = Luhman et al. 2017, J/AJ/153/46
R10 = Rebull et al. 2010, J/ApJS/186/259
Note (3):
b = Luhman+ 2007ApJ...666.1219L 2007ApJ...666.1219L report the extinction at J band.
From those values we computed the AV in this table using the
interstellar extinction law in Cardelli+ (1989) and an Rv of 3.1.
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Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 10 A10 --- Name Common name
12- 13 A2 --- l_FOI [≤] Limit flag on FOI
15- 18 F4.2 10-18W/m2 FOI [2.2/5.2] Herschel/PACS [OI] flux density
20- 23 F4.2 10-18W/m2 e_FOI [1/1.3]? FOI uncertainty
25- 26 A2 --- l_F63 [≤] Limit flag on F63
28- 32 F5.1 mJy F63 [98/359] Herschel/PACS 63.2um line flux
34- 37 F4.1 mJy e_F63 [32/51]? F63 uncertainty
39- 40 A2 --- l_F189 [≤] Limit flag on F189
42- 46 F5.1 mJy F189 [66/318] Herschel/PACS 189um line flux
48- 51 F4.1 mJy e_F189 [40/84]? F189 uncertainty
53- 55 I3 mJy F70 [36/266]? 70um line flux
57- 58 I2 mJy e_F70 [1/17]? F70 uncertainty
60- 62 A3 --- r_F70 Reference for F70 (1)
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Note (1): Reference as follows:
B14 = Bulger et al. 2014, J/A+A/570/A29
R10 = Rebull et al. 2010, J/ApJS/186/259
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Byte-by-byte Description of file: table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 17 A17 --- 2MASS 2MASS name; JHHMMSSss+DDMMSSs
19- 25 F7.5 Jy F0.875 [0.0001/0.005]? Flux at 0.875um
27- 36 F10.8 Jy F1.25 [0.001/0.08] Flux 2MASS (J) at 1.25um
38- 47 F10.8 Jy F1.75 [0.002/0.2] Flux 2MASS (H) at 1.75um
49- 58 F10.8 Jy F2.5 [0.004/0.2] Flux 2MASS (Ks) at 2.5um
60- 66 F7.5 Jy F3.35001 [0.01/0.2]? Flux WISE (W1) at 3.35001um
68- 74 F7.5 Jy F4.49302 [0.01/0.2]? Flux Spitzer/IRAC at 4.49302um
76- 82 F7.5 Jy F5.73096 [0.01/0.2]? Flux Spitzer/IRAC at 5.73096um
84- 90 F7.5 Jy F7.87208 [0.01/0.2]? Flux Spitzer/IRAC at 7.87208um
92- 98 F7.4 Jy F11.5598 [0.02/0.2]? Flux at 11.5598um
100-106 F7.4 Jy F23.6747 [0.05/0.3]? Flux Spitzer/MIPS at 23.6747um
108-114 F7.4 Jy F70.0008 [0.07/0.3]? Flux Herschel/PACS at 70.0008um
116-123 F8.4 Jy F100.0 [0.03/0.3]? Flux Herschel/PACS at 100.0um
125-132 F8.4 Jy F160.0 [0.03/0.3]? Flux at 160.0um
134-138 F5.1 mJy F189.0 [66/318] Herschel/PACS flux at 189.0um
140-147 F8.4 Jy F890.0 [0.004/0.05]? Flux SMA at 890.0um
149-157 F9.4 Jy F1300.0 [0.001/0.02]? Flux at 1300.0um
159-167 F9.4 Jy F2600.0 [0.002/0.008]? Flux IRAM at 2600.0um
169-174 F6.3 Jy F71.42 [0.04/0.2]? Flux Spitzer/MIPS at 71.42um
176-182 F7.3 Jy F100.001 [0.039]? Flux Herschel/PACS at 100.001um
184-189 E6.1 Jy F0.675 [/0.0001]? Flux at 0.675um
191-199 F9.5 Jy F860.0 [0.00087]? Flux JCMT/SCUBA-2 at 860.0um
201-208 F8.4 Jy F850.0 [0.01/46.6]? Flux at 850.0um
210-219 F10.8 Jy F3.4 [0.006/0.06]? Flux at 3.4um
221-230 F10.8 Jy F4.5 [0.006/0.05]? Flux Spitzer/IRAC at 4.5um
232-241 F10.8 Jy F5.8 [0.005/0.05]? Flux Spitzer/IRAC at 5.8um
243-251 F9.7 Jy F8.0 [0.008/0.05]? Flux Spitzer/IRAC at 8.0um
253-262 F10.7 Jy F12.0 [0.01/0.04]? Flux at 12.0um
264-273 F10.7 Jy F24.0 [0.02/0.07]? Flux Spitzer/MIPS at 24.0um
275 A1 --- l_F0.875 Limit flag on flux at 0.875um
286 A1 --- l_F1.25 Limit flag on flux at 1.25um
296 A1 --- l_F1.75 Limit flag on flux at 1.75um
306 A1 --- l_F2.5 Limit flag on flux at 2.5um
315 A1 --- l_F3.35001 Limit flag on flux at 3.35001um
328 A1 --- l_F4.49302 Limit flag on flux at 4.49302um
341 A1 --- l_F5.73096 Limit flag on flux at 5.73096um
354 A1 --- l_F7.87208 Limit flag on flux at 7.87208um
367 A1 --- l_F11.5598 Limit flag on flux at 11.5598um
380 A1 --- l_F23.6747 Limit flag on flux at 23.6747um
393 A1 --- l_F70.0008 Limit flag on flux at 70.0008um
406 A1 --- l_F100.0 Limit flag on flux at 100.0um
417 A1 --- l_F160.0 Limit flag on flux at 160.0um
428 A1 --- l_F189.0 Limit flag on flux at 189.0um
439 A1 --- l_F890.0 Limit flag on flux at 890.0um
450 A1 --- l_F1300.0 Limit flag on flux at 1300.0um
462 A1 --- l_F2600.0 Limit flag on flux at 2600.0um
474 A1 --- l_F71.42 Limit flag on flux at 71.42um
485 A1 --- l_F100.001 Limit flag on flux at 100.001um
498 A1 --- l_F0.675 Limit flag on flux at 0.675um
509 A1 --- l_F860.0 Limit flag on flux at 860.0um
520 A1 --- l_F850.0 Limit flag on flux at 850.0um
531 A1 --- l_F3.4 Limit flag on flux at 3.4um
540 A1 --- l_F4.5 Limit flag on flux at 4.5um
549 A1 --- l_F5.8 Limit flag on flux at 5.8um
558 A1 --- l_F8.0 Limit flag on flux at 8.0um
567 A1 --- l_F12.0 Limit flag on flux at 12.0um
577 A1 --- l_F24.0 Limit flag on flux at 24.0um
587-595 A9 --- r_F0.875 Reference for flux at 0.875um (1)
597-604 A8 --- r_F1.25 Reference for flux at 1.25um (1)
606-613 A8 --- r_F1.75 Reference for flux at 1.75um (1)
615-621 A7 --- r_F2.5 Reference for flux at 2.5um (1)
623-633 A11 --- r_F3.35001 Reference for flux at 3.35001um (1)
635-645 A11 --- r_F4.49302 Reference for flux at 4.49302um (1)
647-657 A11 --- r_F5.73096 Reference for flux at 5.73096um (1)
659-669 A11 --- r_F7.87208 Reference for flux at 7.87208um (1)
671-681 A11 --- r_F11.5598 Reference for flux at 11.5598um (1)
683-693 A11 --- r_F23.6747 Reference for flux at 23.6747um (1)
695-705 A11 --- r_F70.0008 Reference for flux at 70.0008um (1)
707-715 A9 --- r_F100.0 Reference for flux at 100.0um (1)
717-725 A9 --- r_F160.0 Reference for flux at 160.0um (1)
727-735 A9 --- r_F189.0 Reference for flux at 189.0um (1)
737-745 A9 --- r_F890.0 Reference for flux at 890.0um (1)
747-756 A10 --- r_F1300.0 Reference for flux at 1300.0um (1)
758-767 A10 --- r_F2600.0 Reference for flux at 2600.0um (1)
769-777 A9 --- r_F71.42 Reference for flux at 71.42um (1)
779-789 A11 --- r_F100.001 Reference for flux at 100.001um (1)
791-799 A9 --- r_F0.675 Reference for flux at 0.675um (1)
801-809 A9 --- r_F860.0 Reference for flux at 860.0um (1)
811-819 A9 --- r_F850.0 Reference for flux at 850.0um (1)
821-827 A7 --- r_F3.4 Reference for flux at 3.4um (1)
829-835 A7 --- r_F4.5 Reference for flux at 4.5um (1)
837-843 A7 --- r_F5.8 Reference for flux at 5.8um (1)
845-851 A7 --- r_F8.0 Reference for flux at 8.0um (1)
853-860 A8 --- r_F12.0 Reference for flux at 12.0um (1)
862-869 A8 --- r_F24.0 Reference for flux at 24.0um (1)
871-880 A10 --- Name Other name
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Note (1): Reference as follows:
B14 = Bulger et al. (2014, J/A+A/570/A29);
G06 = Guieu et al. (2006, J/A+A/446/485);
L10 = Luhman et al. (2010, J/ApJS/186/111);
M01 = Martin et al. (2001ApJ...561L.195M 2001ApJ...561L.195M);
R10 = Rebull et al. (2010, J/ApJS/186/259);
C03 = Cutri et al. (2003, II/246);
W10 = Wright et al. (2010AJ....140.1868W 2010AJ....140.1868W);
A13 = Andrews et al. (2013, J/ApJ/771/129);
M13 = Mohanty et al. (2013, J/ApJ/773/168);
S09 = Schaefer et al. (2009ApJ...701..698S 2009ApJ...701..698S);
K03 = Klein et al. (2003ApJ...593L..57K 2003ApJ...593L..57K);
G07 = Guieu et al. (2007A&A...465..855G 2007A&A...465..855G);
L00 = Luhman (2000ApJ...544.1044L 2000ApJ...544.1044L);
P16 = Pascucci et al. (2016, J/ApJ/831/125);
D16 = Daemgen et al. (2016A&A...594A..83D 2016A&A...594A..83D)
L08 = Luhman+ (2008, J/ApJ/675/1375)
H17 = This work.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 24-Jan-2018