J/ApJ/760/26 DA white dwarfs infrared photometry (Barber+, 2012)
The frequency of debris disks at white dwarfs.
Barber S.D., Patterson A.J., Kilic M., Leggett S.K., Dufour P., Bloom J.S.,
Starr D.L.
<Astrophys. J., 760, 26 (2012)>
=2012ApJ...760...26B 2012ApJ...760...26B
ADC_Keywords: Stars, white dwarf ; Photometry, infrared ; Stars, masses ;
Effective temperatures
Keywords: infrared: planetary systems; infrared: stars; white dwarfs
Abstract:
We present near- and mid-infrared photometry and spectroscopy from
PAIRITEL, IRTF, and Spitzer of a metallicity-unbiased sample of 117
cool, hydrogen-atmosphere white dwarfs (WDs) from the Palomar-Green
survey and find five with excess radiation in the infrared,
translating to a 4.3+2.7-1.2% frequency of debris disks. This is
slightly higher than, but consistent with the results of previous
surveys. Using an initial-final mass relation, we apply this result to
the progenitor stars of our sample and conclude that 1-7M☉ stars
have at least a 4.3% chance of hosting planets; an indirect probe of
the intermediate-mass regime eluding conventional exoplanetary
detection methods. Alternatively, we interpret this result as a limit
on accretion timescales as a fraction of WD cooling ages; WDs accrete
debris from several generations of disks for ∼10Myr. The average total
mass accreted by these stars ranges from that of 200km asteroids to
Ceres-sized objects, indicating that WDs accrete moons and dwarf
planets as well as solar system asteroid analogs.
Description:
We obtained simultaneous JHKs imaging of 78 WDs using the Peters
Automated Infrared Imaging Telescope (PAIRITEL) between 2009 February
and 2010 April.
We obtained low-resolution near-infrared spectra of 41 WDs over
several nights in 2011 April, August, and September using the 3m NASA
InfraRed Telescope Facility (IRTF) equipped with the 0.8-5.4 Micron
Medium-Resolution Spectrograph and Imager.
We used the warm Spitzer equipped with the InfraRed Array Camera
(IRAC) to obtain infrared photometry of 11 WDs between 2010 September
and 2011 February for program number 70023.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 88 117 Sample properties
table2.dat 30 11 Spitzer Cycle 7 photometry fluxes in IRAC
channels 1 (3.6um) and 2 (4.5um).
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See also:
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
II/207 : Palomar-Green catalog UV-excess stellar objects (Green+ 1986)
J/AJ/146/34 : IR photometry of DA white dwarfs from LAMOST (Zhang+, 2013)
J/MNRAS/417/1210 : DA-white dwarfs from SDSS and UKIDSS (Girven+, 2011)
J/ApJS/197/38 : The WIRED survey. II. (Debes+, 2011)
J/A+A/466/627 : Parameters of DA white dwarfs in SDSS-DR1 (Hu+, 2007)
J/AJ/132/1221 : VJHK and SDSS photometry of DA white dwarfs (Holberg+, 2006)
J/ApJ/631/1100 : Atmospheric parameters of DA white dwarfs (Gianninas+, 2005)
J/ApJS/161/394 : Low-luminosity companions to white dwarfs (Farihi+, 2005)
J/ApJS/156/47 : DA WDs from the Palomar Green Survey (Liebert+, 2005)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 A8 --- PG The Palomar Green Survey identification (1)
10- 14 I5 K Teff [9520/22460] Effective temperature (1)
16- 19 F4.2 [cm/s2] logg [7.3/9] Surface gravity (1)
21- 24 F4.2 Msun Mass [0.4/1.2] White dwarf mass (1)
26- 28 F3.1 Msun M* [0.1/7.2] Progenitor Main Sequence mass (2)
30- 33 I4 Myr tau [11/2692] Cooling time
35- 40 F6.3 mag Jmag [12.9/17] J-band magnitude
42- 46 F5.3 mag e_Jmag [0.006/0.2] Jmag uncertainty
48- 53 F6.3 mag Hmag [12.9/17]? H-band magnitude
55- 59 F5.3 mag e_Hmag [0.009/0.3]? Hmag uncertainty
61- 66 F6.3 mag Kmag [12.6/17]? Ks-band magnitude
68- 72 F5.3 mag e_Kmag [0.01/0.3]? Kmag uncertainty
74- 82 A9 --- Ref Reference(s) (3)
84- 88 A5 --- Src Data source (I=IRTF, S=Spitzer or P=PAIRITEL)
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Note (1): From Liebert et al. 2005, Cat. J/ApJS/156/47
Note (2): We estimate the progenitor MS masses using the initial-final mass
relation derived by Kalirai et al. (2008ApJ...676..594K 2008ApJ...676..594K) and
Williams et al. (2009ApJ...693..355W 2009ApJ...693..355W).
Note (3): References as follows:
1 = This work;
2 = Reach et al. 2005PASP..117..978R 2005PASP..117..978R
3 = Mullally et al. 2007ApJS..171..206M 2007ApJS..171..206M
4 = Jura et al. 2007ApJ...663.1285J 2007ApJ...663.1285J
5 = Farihi et al. 2008ApJ...674..431F 2008ApJ...674..431F
6 = Reach et al. 2009ApJ...693..697R 2009ApJ...693..697R
7 = Farihi et al. 2009ApJ...694..805F 2009ApJ...694..805F
8 = Kilic et al. 2009ApJ...705.1219K 2009ApJ...705.1219K
9 = Kilic et al. 2010ApJ...708..411K 2010ApJ...708..411K
10 = Xu & Jura 2012ApJ...745...88X 2012ApJ...745...88X
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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- 8 A8 --- PG The Palomar Green Survey identification
10- 14 F5.1 uJy [3.6] [42.5/436] Spitzer/IRAC 3.6um flux
16- 19 F4.1 uJy e_[3.6] [1.5/13.5] 3.6um flux uncertainty
21- 25 F5.1 uJy [4.5] [26.6/484] Spitzer/IRAC 4.5um flux
27- 30 F4.1 uJy e_[4.5] [1.3/15] 4.5um flux uncertainty
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History:
From electronic version of the journal
(End) Emmanuelle Perret [CDS] 23-Jul-2014