V/144 Near-IR spectroscopy of low-mass binaries and brown dwarfs (Mace, 2014)
Investigating low-mass binary stars and brown dwarfs with near-infrared
spectroscopy
Mace G.N.
<Thesis, University of California, Los Angeles (2014)>
=2014yCat.5144....0M 2014yCat.5144....0M
ADC_Keywords: Stars, dwarfs ; Stars, double and multiple ;
Infrared sources ; Photometry, infrared
Abstract:
The mass of a star at formation determines its subsequent evolution
and demise. Low-mass stars are the most common products of star
formation and their long main-sequence lifetimes cause them to
accumulate over time. Star formation also produces many
substellar-mass objects known as brown dwarfs, which emerge from their
natal molecular clouds and continually cool as they age, pervading the
Milky Way. Low-mass stars and brown dwarfs exhibit a wide range of
physical characteristics and their abundance make them ideal subjects
for testing formation and evolution models. I have examined a pair of
pre-main sequence spectroscopic binaries and used radial velocity
variations to determine orbital solutions and mass ratios.
Additionally, I have employed synthetic spectra to estimate their
effective temperatures and place them on theoretical
Hertzsprung-Russell diagrams. From this analysis I discuss the
formation and evolution of young binary systems and place bounds on
absolute masses and radii. I have also studied the late-type T dwarfs
revealed by the Wide-field Infrared Survey Explorer (WISE). This
includes the exemplar T8 subdwarf Wolf 1130C, which has the lowest
inferred metallicity in the literature and spectroscopic traits
consistent with old age. Comparison to synthetic spectra implies that
the dispersion in near-infrared colors of late-type T dwarfs is a
result of age and/or thin sul de clouds. With the updated census of
the L, T, and Y dwarfs we can now study specific brown dwarf
subpopulations. Finally, I present a number of future studies that
would develop our understanding of the physical qualities of T dwarf
color outliers and disentangle the tracers of age and atmospheric
properties.
The thesis is available at:
http://www.astro.ucla.edu/~gmace/thesis.html
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table41.dat 110 104 WISE All-Sky photometry for discoveries from
Kirkpatrick et al. (2011, Cat. J/ApJS/197/19)
table42.dat 110 102 WISE All-Sky photometry for brown dwarf
discoveries from this work
table61.dat 82 218 Peak-Flux ratios for T Dwarfs in Mace et al.,
2013ApJ...777...36M 2013ApJ...777...36M
table62.dat 56 103 Spectrophotometric distance estimates to objects
from Mace et al., 2013, J/ApJS/205/6,
2013ApJ...777...36M 2013ApJ...777...36M
table63.dat 37 26 The L, T, and Y dwarf census through 2014
February discovery survey
table64.dat 135 1565 The brown dwarf census through 2014 February
refs.dat 227 195 References
--------------------------------------------------------------------------------
See also:
II/311 : WISE All-Sky Data Release (Cutri+ 2012)
J/ApJS/190/100 : NIR proper motion survey using 2MASS (Kirkpatrick+, 2010)
J/ApJS/197/19 : First brown dwarfs discovered by WISE (Kirkpatrick+, 2011)
J/AJ/142/77 : New T dwarfs identified in Pan-STARRS 1 (Deacon+, 2011)
J/ApJ/753/156 : T/Y brown dwarfs with WISE photometry (Kirkpatrick+, 2012)
J/ApJS/205/6 : T dwarf population revealed by WISE (Mace+, 2013)
Byte-by-byte Description of file: table41.dat table42.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 A4 --- --- [WISE]
6- 26 A21 --- WISE WISE name (JHHMMSS.ss+DDMMSS.s, II/311)
27 A1 --- n_WISE Note on source (G1)
29- 41 A13 --- SpType Spectral type from Kirkpatricket al. 2011
(J/ApJS/197/19)
43 A1 --- l_W1mag Limit flag on W1mag
44- 48 F5.2 mag W1mag W1 (3.35um) magnitude
50- 53 F4.2 mag e_W1mag ? rms uncertainty on W1mag
55- 59 F5.2 mag W2mag W2 (4.6um) magnitude
61- 64 F4.2 mag e_W2mag ? rms uncertainty on W2mag
66 A1 --- l_W3mag Limit flag on W3mag
67- 71 F5.2 mag W3mag W3 (11.6um) magnitude
73- 76 F4.2 mag e_W3mag ? rms uncertainty on W3mag
78 A1 --- l_W4mag Limit flag on W4mag
79- 83 F5.2 mag W4mag W4 (22.1um) magnitude
85- 88 F4.2 mag e_W4mag ? rms uncertainty on W4mag
90 A1 --- l_W1-W2 Limit flag on W1-W2
91- 94 F4.2 mag W1-W2 W1-W2 colour index
96- 99 F4.2 mag e_W1-W2 ? rms uncertainty on W1-W2
101 A1 --- l_W2-W3 Limit flag on W2-W3
102-105 F4.2 mag W2-W3 W2-W3 colour index
107-110 F4.2 mag e_W2-W3 ? rms uncertainty on W2-W3
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table61.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1 A1 --- Sample [A-E] Sample (1)
3- 19 A17 --- Name Object name (some names are truncated)
21- 35 A15 --- Inst Instrument
37- 45 A9 --- SpType NIR spectral type (2)
47- 51 F5.3 --- Y/J ?=- Y/J peak-flux ratio
53- 57 F5.3 --- e_Y/J ? rms uncertainty on Y/J
59- 63 F5.3 --- H/J ?=- H/J peak-flux ratio
65- 69 F5.3 --- e_H/J ? rms uncertainty on H/J
71- 76 F6.3 --- K/J ?=- K/J peak-flux ratio
78- 82 F5.3 --- e_K/J ? rms uncertainty on K/J
--------------------------------------------------------------------------------
Note (1): Sample as follows:
A = T and Y Dwarf Standards
B = T Dwarf Discoveries from Kirkpatrick et al. (2011, J/ApJS/197/19)
C = New T Dwarf Discoveries
D = T Dwarfs from table46.dat
E = Y Dwarfs from Cushing et al. (2011ApJ...743...50C 2011ApJ...743...50C) and
Kirkpatrick et al. (2012, J/ApJ/753/156)
Note (2): Spectra from Adam Burgasser's SpeX Prism Spectral Library.
Classification notes:
pec = peculiar
sb = spectral binary
: = low SNR
extr. red = extremely red, discussed in Sect. 4.4.2
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table62.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 A4 --- --- [WISE]
6- 26 A21 --- WISE WISE name (JHHMMSS.ss+DDMMSS.s, II/311)
27 A1 --- n_WISE Note on source (G1)
29- 33 F5.2 mag W2mag W2 (4.6um) magnitude
35- 47 A13 --- SpType Spectral type
49- 53 F5.2 mag W2MAG Absolute W2 magnitude (2)
55- 56 I2 pc Dist [7/46] Distance (±3pc)
--------------------------------------------------------------------------------
Note (2): Estimated absolute W2 magnitude based on the relationships provided by
Kirkpatrick et al. (2011, J/ApJS/197/19 and 2012, J/ApJ/753/156).
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table63.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 A8 --- SpType Spectral Type (1)
10- 12 I3 --- SDSS Number of stars with the spectral type in SDSS
14- 16 I3 --- 2MASS Number of stars with the spectral type in 2MASS
18- 19 I2 --- DENIS Number of stars with the spectral type in DENIS
21- 22 I2 --- Other Number of stars with the spectral type in
other surveys (2)
24- 25 I2 --- CFBDS Number of stars with the spectral type in CFBDS
27- 29 I3 --- UKIDSS Number of stars with the spectral type in UKIDSS
31- 33 I3 --- WISE Number of stars with the spectral type in WISE
35- 37 I3 --- Total Total of stars with the spectral type
--------------------------------------------------------------------------------
Note (1): Spectral types are all near-infrared types and half-types have been
rounded down (e.g. a T4.5 is counted as a T4). Optical spectral types were
converted using the relation in Figure 6.8.
Note (2): Directly imaged companions and other serendipitous discoveries not
initially identified by one of the other surveys.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table64.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 35 A35 --- Name Discovery name(s)
37- 51 A15 --- r_Name Discovery reference, in refs.dat file
53- 63 F11.7 deg RAdeg Right ascension (J2000)
65- 75 F11.7 deg DEdeg Declination (J2000)
77- 86 A10 --- OType Optical type (1)
88-103 A16 --- r_OType Optical type reference, in refs.dat file
105-119 A15 --- NIRType Near-IR type (1)
121-135 A15 --- r_NIRType Near-IR type reference, in refs.dat file
--------------------------------------------------------------------------------
Note (1): Classification notes:
p = peculiar
: = low SNR
red = red classifications from Kirkpatrick et al.
(2010, J/ApJS/190/100) and Gagne et al. (2014ApJ...783..121G 2014ApJ...783..121G)
blue = blue classifications from Kirkpatrick et al. 2010 (J/ApJS/190/100)
and Gagne et al. (2014ApJ...783..121G 2014ApJ...783..121G)
--------------------------------------------------------------------------------
Byte-by-byte Description of file: refs.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 16 A16 --- Ref Reference code
19- 37 A19 --- BibCode BibCode
39- 65 A27 --- Aut Author's name
66-227 A162 --- Com Comments
--------------------------------------------------------------------------------
Global notes:
Note (G1): Notes as follows:
a = L dwarf candidate, Aberasturi et al. (2011A&A...534L...7A 2011A&A...534L...7A)
b = ULAS J095047.28+011734.3, Leggett et al. (2012ApJ...748...74L 2012ApJ...748...74L)
c = IR source, Andrei et al. (2011AJ....141...54A 2011AJ....141...54A)
d = LHS 2803B, Deacon et al. (2012ApJ...757..100D 2012ApJ...757..100D)
e = BD +011734 2920B, Pinfield et al. (2012MNRAS.422.1922P 2012MNRAS.422.1922P)
f = T7 candidates, Scholz (2010A&A...515A..92S 2010A&A...515A..92S)
g = PSO J226.2599-28.8959, PSO J246.4222+15.4698, PSO J247.3273+03.5932,
Deacon et al. 2011 (J/AJ/142/77)
h = VHS J154352.78-043909.6, Lodieu et al. (2012A&A...548A..53L 2012A&A...548A..53L)
i = WISE J180901.07+383805.4, Luhman et al. (2012ApJ...760..152L 2012ApJ...760..152L)
j = A nearby object caused source confusion in the pipeline used to generate
the All-Sky Catalog, resulting in a non-detection of this object. The
magnitudes reported here were taken from the first-pass processing
operations co-add Source Working Database (WISEPC, J/ApJS/190/100).
* = Scholz et al. (2011A&A...532L...5S 2011A&A...532L...5S) independently discovered the T9
dwarf WISE J1741+2553, first announced in Gelino et al.
(2011AJ....142...57G 2011AJ....142...57G), and also noted WISE J0254+0223 as a proper
motion object of presumably late type.
--------------------------------------------------------------------------------
Acknowledgements:
Gregory Mace, mace.gregory(at)gmail.com
(End) Patricia Vannier [CDS] 21-May-2014