Synthetic Spectra and Color-Temperature Relations of M Giants

Abstract

As part of a project to model the integrated spectra and colors of elliptical galaxies through evolutionary synthesis, we have refined our synthetic spectrum calculations of M giants. After critically assessing three effective temperature scales for M giants, we adopted the relation of Dyck et al. (1996) for our models. Using empirical spectra of field M giants as a guide, we then calculated MARCS stellar atmosphere models and SSG synthetic spectra of these cool stars, adjusting the band absorption oscillator strengths of the TiO bands to better reproduce the observational data. The resulting synthetic spectra are found to be in very good agreement with the K-band spectra of stars of the appropriate spectral type taken from Kleinmann & Hall (1986) as well. Spectral types estimated from the strengths of the TiO bands and the depth of the bandhead of CO near 2.3 microns quantitatively confirm that the synthetic spectra are good representations of those of field M giants. The broad-band colors of the models match the field relations of K and early-M giants very well; for late-M giants, differences between the field-star and synthetic colors are probably caused by the omission of spectral lines of VO and water in the spectrum synthesis calculations. Here, we present four grids of K-band bolometric corrections and colors -- Johnson U-V and B-V; Cousins V-R and V-I; Johnson-Glass V-K, J-K and H-K; and CIT/CTIO V-K, J-K, H-K and CO -- for models having 3000 K < Teff < 4000 K and -0.5 < log g < 1.5. These grids, which have [Fe/H] = +0.25, 0.0, -0.5 and -1.0, extend and supplement the color-temperature relations of hotter stars presented in a companion paper (astro-ph/9911367).

To appear in the March 2000 issue of the Astronomical Journal. 60 pages including 15 embedded postscript figures (one page each) and 6 embedded postscript tables (10 pages total)

References in corpus (1)

• Synthetic Spectra and Color-Temperature Relations of M Giants

Cited by in corpus (65)

• Theoretical isochrones in several photometric systems I. Johnson-Cousins-Glass, HST/WFPC2, HST/NICMOS, Washington, and ESO Imaging Survey filter sets
• An empirical formula for the mass-loss rates of dust-enshrouded red supergiants and oxygen-rich Asymptotic Giant Branch stars
• Evolutionary synthesis of galaxies at high spectral resolution with the code PEGASE-HR
• Improved Color-Temperature Relations and Bolometric Corrections for Cool Stars
• An Empirical UBVRIJHK Color-Temperature Calibration for Stars
• The Evolution of Massive Stars. I. Red Supergiants in the Magellanic Clouds
• Gravity Indicators in the Near-Infrared Spectra of Brown Dwarfs
• A 2MASS All-Sky View of the Sagittarius Dwarf Galaxy: Variation of the Metallicity Distribution Function Along the Sagittarius Stream
• Identification of the donor in the X-ray binary GRS 1915+105
• Synthetic Spectra and Color-Temperature Relations of M Giants
• Broad-band photometric colors and effective temperature calibrations for late-type giants. I. Z=0.02
• A census of symbiotic stars in the 2MASS, WISE and Gaia surveys
• The pulsation modes, masses and evolution of luminous red giants
• Constraining the structure and formation of the Galactic bulge from a field in its outskirts. FLAMES-GIRAFFE spectra of about 400 red giants around (l,b)=(0°,-10°)
• Globular Cluster Abundances from High-Resolution Integrated Light Spectra, I: 47 Tuc
• Synthetic photometry for M and K giants and stellar evolution: hydrostatic dust-free model atmospheres and chemical abundances
• Long Secondary Periods in Variable Red Giants
• Gemini-Phoenix infrared high-resolution abundance analysis of five giants in the bulge globular cluster NGC 6553
• What causes the large extensions of red-supergiant atmospheres? Comparisons of interferometric observations with 1-D hydrostatic, 3-D convection, and 1-D pulsating model atmospheres
• Long period variables in 47 Tuc: direct evidence for lost mass
• Two new free-floating or wide-orbit planets from microlensing
• Empirically Constrained Color-Temperature Relations. II. uvby
• Abundances in intermediate-mass AGB stars undergoing third dredge-up and hot-bottom burning
• Predicting the Fate of Binary Red Giants Using the Observed Sequence E Star Population: Binary Planetary Nebula Nuclei and Post-RGB Stars
• A Two Micron All-Sky Survey View of the Sagittarius Dwarf Galaxy: VI. s-Process and Titanium Abundance Variations Along the Sagittarius Stream
• Three dimensional interstellar extinction map towards the Galactic Bulge
• Ellipsoidal Variability and Long Secondary Periods in MACHO Red Giant Stars
• PSR J1740-3052 - a pulsar with a massive companion
• AGB stars of the intermediate-age LMC cluster NGC 1846 II. Dredge up along the AGB
• Identifying Contributions to the Stellar Halo from Accreted, Kicked-Out, and In Situ Populations
• The Pulsation of AGB Stars in the Magellanic Cloud Clusters NGC 1978 and NGC 419
• Exploring Halo Substructure with Giant Stars: The Nature of the Triangulum-Andromeda Stellar Features
• A spectral atlas of post-main-sequence stars in omega Centauri: kinematics, evolution, enrichment and interstellar medium
• Lithium abundances along the RGB: FLAMES-GIRAFFE spectra of a large sample of low-mass Bulge stars
• The light curve of the semiregular variable L2 Puppis: I. A recent dimming event from dust
• The Chemical Evolution of the Monoceros Ring/Galactic Anticenter Stellar Structure
• Envelope tomography of long-period variable stars III. Line-doubling frequency among Mira stars
• Limb-darkening measurements for a cool red giant in microlensing event OGLE 2004-BLG-482
• Broad-band photometric colors and effective temperature calibrations for late-type giants. II. Z<0.02
• Technetium and the third dredge up in AGB stars. I. Field stars
• The Very Slow Wind From the Pulsating Semiregular Red Giant L2 Pup
• Full orbital solution for the binary system in the northern Galactic disc microlensing event Gaia16aye
• Synthetic photometry for carbon-rich giants. III. Tracing the sequence of mass-losing galactic C-type Miras
• The AGB stars of the intermediate-age LMC cluster NGC 1846 Variability and age determination
• IGR J17329-2731: The birth of a symbiotic X-ray binary
• Eccentric Ellipsoidal Red Giant Binaries in the LMC: Complete Orbital Solutions and Comments on Interaction at Periastron
• An abundance analysis of the symbiotic star CH Cyg
• The puzzling dredge-up pattern in NGC 1978
• The Orbital Nature of 81 Ellipsoidal Red Giant Binaries in the Large Magellanic Cloud
• First Chemical Analysis of Stars in The Triangulum-Andromeda Star Cloud
• ChaMPlane Discovery of Candidate Symbiotic Binaries in Baade's and Stanek's Windows
• The recurrent nova RS Oph - simultaneous B and V band observations of the flickering variability
• IRAS12556-7731: a "chamaeleonic" lithium-rich M-giant
• Using broadband photometry to examine the nature of Long Secondary Periods in red giants
• Long period variables and mass loss in the globular clusters NGC 362 and NGC 2808
• Long Secondary Periods in luminous red giant variables
• Galactic S Stars: Investigations of Color, Motion, and Spectral Features
• Single Stellar Populations in the Near-Infrared - I. Preparation of the IRTF spectral stellar library
• Optical tracking of deep-space spacecraft in Halo L2 orbits and beyond: the Gaia mission as a pilot case
• The 2010 early outburst spectrum of the recurrent nova U Scorpii
• A possible surviving companion of the SN Ia in the Galactic SNR G272.2-3.2
• The LMC HII region N 214C and its peculiar nebular blob
• The symbiotic binary ZZ CMi: intranight variability and suggested outbursting nature
• Radial Velocity Curves of Ellipsoidal Red Giant Binaries in the Large Magellanic Cloud
• Gaia20fnr: A binary-lens microlensing event with full orbital motion revealed by four space telescopes