J/AJ/155/38 The rotation of M dwarfs observed by APOGEE (Gilhool+, 2018)
The rotation of M dwarfs observed by the Apache Point Galactic Evolution
Experiment.
Gilhool S.H., Blake C.H., Terrien R.C., Bender C., Mahadevan S.,
Deshpande R.
<Astron. J., 155, 38 (2018)>
=2018AJ....155...38G 2018AJ....155...38G (SIMBAD/NED BibCode)
ADC_Keywords: Stars, dwarfs ; Stars, M-type ; Stars, late-type ;
Effective temperatures ; Abundances ; Rotational velocities
Keywords: stars: fundamental parameters - stars: late-type - stars: low-mass -
stars: rotation
Abstract:
We present the results of a spectroscopic analysis of rotational
velocities in 714 M-dwarf stars observed by the SDSS-III Apache Point
Galactic Evolution Experiment (APOGEE) survey. We use a template-fitting
technique to estimate v sin i while simultaneously estimating log g,
[M/H], and Teff. We conservatively estimate that our detection limit
is 8 km/s. We compare our results to M-dwarf rotation studies in the
literature based on both spectroscopic and photometric measurements.
Like other authors, we find an increase in the fraction of rapid
rotators with decreasing stellar temperature, exemplified by a sharp
increase in rotation near the M4 transition to fully convective
stellar interiors, which is consistent with the hypothesis that fully
convective stars are unable to shed angular momentum as efficiently as
those with radiative cores. We compare a sample of targets observed
both by APOGEE and the MEarth transiting planet survey and find no
cases where the measured v sin i and rotation period are physically
inconsistent, requiring sin i>1. We compare our spectroscopic results
to the fraction of rotators inferred from photometric surveys and find
that while the results are broadly consistent, the photometric surveys
exhibit a smaller fraction of rotators beyond the M4 transition by a
factor of ∼2. We discuss possible reasons for this discrepancy. Given
our detection limit, our results are consistent with a bimodal
distribution in rotation that is seen in photometric surveys.
Description:
We present an analysis of the rotation of more than 700 M dwarfs
observed as part of the Apache Point Observatory Galactic Evolution
Experiment (APOGEE; Majewski et al. 2017AJ....154...94M 2017AJ....154...94M). Specifically,
we analyze infrared spectra from the APOGEE M Dwarf Survey
(Deshpande et al. 2013, J/AJ/146/156), an ancillary science program that
was carried out as part of the Sloan Digital Sky Survey (SDSS-III;
Eisenstein et al. 2011AJ....142...72E 2011AJ....142...72E).
We analyzed APOGEE spectra from SDSS Data Release 13 (SDSS
Collaboration et al. 2016, arXiv:1608.02013), observed using the SDSS main
2.5 m telescope (Gunn et al. 2006AJ....131.2332G 2006AJ....131.2332G). The APOGEE spectrograph
is a multiplexed, cryogenic, high-resolution (R∼22500) fiber-fed
instrument. It covers the H-band (λ=1.514-1.696 µm) across three
near-infrared detectors; blue (λ=1.52-1.58 µm), green
(λ=1.59-1.64 µm), and red (λ=1.65-1.69 µm)
(Wilson et al. 2010SPIE.7735E..1CW; Skrutskie & Wilson 2015arXiv150308918S 2015arXiv150308918S).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table4.dat 74 714 v sin i results
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See also:
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
J/A+A/331/581 : Rotation and activity in field M dwarfs (Delfosse+ 1998)
J/ApJ/704/975 : Rotational velocities for M dwarfs (Jenkins+, 2009)
J/MNRAS/407/1657 : Rotation velocities of dwarf M stars (Houdebine, 2010)
J/AJ/143/93 : Rotational velocities in early-M stars (Reiners+, 2012)
J/AJ/146/156 : APOGEE M-dwarf survey. I. First year velocities
(Deshpande+, 2013)
J/MNRAS/432/1203 : Rotation periods of M-dwarf stars (McQuillan+, 2013)
J/AJ/151/144 : ASPCAP weights for the 15 APOGEE chemical elements
(Garcia+, 2016)
J/MNRAS/460/2611 : APOGEE K and M dwarfs (Schmidt+, 2016)
J/MNRAS/463/1844 : M dwarfs rotation-activity relation (Stelzer+, 2016)
J/ApJ/837/96 : Rotation-Activity Correlations in K-M dwarfs II.
(Houdebine+, 2017)
Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 17 A17 --- 2MASS 2MASS identifier (JHHMMSSss+DDMMSSs)
19- 30 F12.8 deg RAdeg Right Ascension in decimal degrees (J2000)
32- 44 F13.9 deg DEdeg Declination in decimal degrees (J2000)
46- 49 I4 K Teff-A [2610/3999] ASPCAP derived effective
temperature (1)
51- 54 I4 K Teff-V [2600/4000] VFIT derived effective temperature
(2)
56- 59 F4.1 [Sun] [M/H] [-1.5/0.5] VFIT derived metallicity (2)
61- 63 F3.1 [cm/s2] logg [4.5/5.5] VFIT derived log surface gravity (2)
65 A1 --- l_vsini [<] Limit flag on vsini
66- 70 F5.2 km/s vsini [8/52.8] VFIT derived projected rotation
velocity (2)
72- 74 F3.1 km/s e_vsini [0/2.7]? Uncertainty in vsini
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Note (1): APOGEE Stellar Parameters and Chemical Abundance Pipeline (ASPCAP;
Garcia Perez et al. 2016, J/AJ/151/144).
Note (2): The other primary method for determining v sin i, which we used in
this analysis, is to make a direct, pixel-to-pixel comparison between a high
signal-to-noise spectrum and a library of theoretical templates spanning a
wide range of stellar parameters. The template is convolved with a rotational
broadening kernel, and the kernel that produces the best fit to the data
constitutes the measured value of v sin i (e.g., Jenkins et al. 2009,
J/ApJ/704/975). We refer to this as the "template-fitting technique" or "VFIT"
technique.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Tiphaine Pouvreau [CDS] 19-Sep-2018