The effective temperature scale of M dwarfs

By A. Rajpurohit, Céline Reylé, F. Allard, Derek Homeier, M. Schultheis, M. Bessell, Annie Robin. 2013

173 citations recorded by the source corpus.

Context. Despite their large number in the Galaxy, M dwarfs remain elusive objects and the modeling of their photospheres has long remained a challenge (molecular opacities, dust cloud formation). Aims. Our objectives are to validate the BT-Settl model atmospheres, update the M dwarf Teff-spectral type relation, and find the atmospheric parameters of the stars in our sample. Methods. We compare two samples of optical spectra covering the whole M dwarf sequence with the most recent BT-Settl synthetic spectra and use a � 2 minimization technique to determine Teff. The first sample consists of 97 low-resolution spectra obta ined with NTT at La Silla Observatory. The second sample contains 55 mid-resolution spectra obtained at the Siding Spring Observa tory (SSO). The spectral typing is realized by comparison with already classified M dwarfs. Results. We show that the BT-Settl synthetic spectra reproduce the slope of the spectral energy distribution and most of its featu res. Only the CaOH band at 5570A and AlH and NaH hydrides in the bluepart of the spectra are still missing in the models. The Teff-scale obtained with the higher resolved SSO 2.3 m spectra is consistent with that obtained with the NTT spectra. We compare our Teffscale with those of other authors and to published isochrones using the BT-Settl colors. We also present relations between effective temperature, spectral type and colors of the M dwarfs.

Subfields: Astronomy and Astrophysics, Instrumentation

View Paper: https://www.semanticscholar.org/paper/80d7d673f0fc94bea36d42f39eb112b34ab2b22d

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

In Instrumentation

Citations in the corpus

Improving PARSEC models for very low mass stars (2014, background): “We suspect that this discrepancy originates from some molecular absorption bands around 4400 Å (AlH and NaH) being still unaccounted for in the models, as recently pointed out in Rajpurohit et al. (2013).”
AN EMPIRICAL CALIBRATION TO ESTIMATE COOL DWARF FUNDAMENTAL PARAMETERS FROM H-BAND SPECTRA (2014, background): “…over the last two decades – suffer from incomplete line lists for the molecules that blanket the spectra, particularly for TiO, VO, metal hydrides, and water vapor (e.g. Valenti et al. 1998; Allard et al. 2000; Leggett et al. 2000; Bean et al. 2006;̈Onehag et al. 2012; Rajpurohit et al. 2013).”
New evolutionary models for pre-main sequence and main sequence low-mass stars down to the hydrogen-burning limit (2015, methodology): “A preliminary set of atmosphere models, referred to as the BT-Settl models (Allard et al., 2012a,b; Rajpurohit et al., 2013), include some of these changes, which are briefly summarised below.”
AN OPTICAL SPECTROSCOPIC STUDY OF T TAURI STARS. I. PHOTOSPHERIC PROPERTIES (2014, methodology): “Rajpurohit et al. (2013) recently obtained a new scaling between spectral type and temperature for M dwarfs by comparing BT-Settl synthetic spectra calculated from the Phoenix code (e.g. Allard & Hauschildt 1995; Allard et al. 2012) to observed low-resolution spectra.”
CARMENES input catalogue of M dwarfs. I. Low-resolution spectroscopy with CAFOS (2015, background): “Dwarf stars of M spectral type have effective temperatures between 2300 and 3900 K (Kirkpatrick et al. 2005; Rajpurohit et al. 2013).”
Modeling climate diversity, tidal dynamics and the fate of volatiles on TRAPPIST-1 planets (2017, methodology): “The emission spectrum of TRAPPIST-1 was computed using the synthetic BT-Settl spectrum1 (Rajpurohit et al. 2013) assuming a temperature of 2500 K, a surface gravity of 103 m s−2 and a metallicity of 0 dex.”
How to Constrain Your M Dwarf. II. The Mass–Luminosity–Metallicity Relation from 0.075 to 0.70 Solar Masses (2018, background): “Re- 11Version 2 of MIST isochrones shows better agreement, but was not available at the time this paper was published cent comparison suggest atmospheric models reproduce optical and NIR spectra of M dwarfs to '5% (e.g., Lépine et al. 2013; Mann et al. 2013b), with the exception of a few molecular f”
SPECTRO-THERMOMETRY OF M DWARFS AND THEIR CANDIDATE PLANETS: TOO HOT, TOO COOL, OR JUST RIGHT? (2013, methodology): “We test the set of models that use the Asplund et al. (2009) solar abundances (AGSS), and those using the updated Caffau et al. (2011) revised solar abundances (CIFIST, Allard et al. 2013; Rajpurohit et al. 2013).”
The habitability of Proxima Centauri b II. Possible climates and Observability (2016, methodology): “The emission spectrum of Proxima Centauri (see Figure 2, top panel) was computed using the synthetic BT-Settl spectrum2 (Rajpurohit et al. 2013) of a M5.”
HOW TO CONSTRAIN YOUR M DWARF: MEASURING EFFECTIVE TEMPERATURE, BOLOMETRIC LUMINOSITY, MASS, AND RADIUS (2015, background): “While this is reasonable for warmer stars, M dwarfs have significantly more flux in the NIR than predicted by a blackbody (Rajpurohit et al. 2013).”
BANYAN. II. VERY LOW MASS AND SUBSTELLAR CANDIDATE MEMBERS TO NEARBY, YOUNG KINEMATIC GROUPS WITH PREVIOUSLY KNOWN SIGNS OF YOUTH (2013, methodology): “We have assumed an IMF described in Section 3.1 to assign masses to these synthetic objects, and in turn converted them to MW1 magnitudes using the AMES-Cond isochrones (Baraffe et al. 2003) in combination with CIFIST2011 BTSETTL atmosphere models (Allard et al. 2013, Rajpurohit et al. 2013).”