Spectroscopic constants, abundances, and opacities of the TiH molecule

A  Burrows; M  Dulick; C W  Bauschlicher; P F  Bernath; R S  Ram; C M  Sharp; J A  Milsom

Spectroscopic constants, abundances, and opacities of the TiH molecule

A Burrows, M Dulick, C W Bauschlicher, P F Bernath, R S Ram, C M Sharp, J A Milsom

Chemistry

Research output: Contribution to journal › Article › peer-review

Abstract

Using previous measurements and quantum chemical calculations to derive the molecular properties of the TiH molecule, we obtain new values for its rovibrational constants, thermochemical data, spectral line lists, line strengths, and absorption opacities. Furthermore, we calculate the abundance of TiH in M and L dwarf atmospheres and conclude that it is much higher than previously thought. We find that the TiH/TiO ratio increases strongly with decreasing metallicity, and at high temperatures can exceed unity. We suggest that, particularly for subdwarf L and M dwarfs, spectral features of TiH near &SIM; 0.52 and 0.94 μ m and in the H band may be more easily measurable than heretofore thought. The recent possible identification in the L subdwarf 2MASS J0532 of the 0.94 μ m feature of TiH is in keeping with this expectation. We speculate that looking for TiH in other dwarfs and subdwarfs will shed light on the distinctive titanium chemistry of the atmospheres of substellar-mass objects and the dimmest stars.

Original language	English
Pages (from-to)	988-1002
Number of pages	15
Journal	The Astrophysical Journal
Volume	624
Issue number	2
Publication status	Published - 10 May 2005

Keywords

infrared : stars
stars : atmospheres
stars : fundamental parameters
stars : low-mass, brown dwarfs
subdwarfs
TRANSITION-METAL HYDRIDES
ALL-SKY SURVEY
BROWN DWARF
ROTATIONAL ANALYSIS
DISCOVERY
EQUILIBRIUM
SPECTRUM
STATES
2MASS
CRH

Cite this

@article{3128d22e35c84f1a8468d03d9fcfec7b,

title = "Spectroscopic constants, abundances, and opacities of the TiH molecule",

abstract = "Using previous measurements and quantum chemical calculations to derive the molecular properties of the TiH molecule, we obtain new values for its rovibrational constants, thermochemical data, spectral line lists, line strengths, and absorption opacities. Furthermore, we calculate the abundance of TiH in M and L dwarf atmospheres and conclude that it is much higher than previously thought. We find that the TiH/TiO ratio increases strongly with decreasing metallicity, and at high temperatures can exceed unity. We suggest that, particularly for subdwarf L and M dwarfs, spectral features of TiH near &SIM; 0.52 and 0.94 μ m and in the H band may be more easily measurable than heretofore thought. The recent possible identification in the L subdwarf 2MASS J0532 of the 0.94 μ m feature of TiH is in keeping with this expectation. We speculate that looking for TiH in other dwarfs and subdwarfs will shed light on the distinctive titanium chemistry of the atmospheres of substellar-mass objects and the dimmest stars.",

keywords = "infrared : stars, stars : atmospheres, stars : fundamental parameters, stars : low-mass, brown dwarfs, subdwarfs, TRANSITION-METAL HYDRIDES, ALL-SKY SURVEY, BROWN DWARF, ROTATIONAL ANALYSIS, DISCOVERY, EQUILIBRIUM, SPECTRUM, STATES, 2MASS, CRH",

author = "A Burrows and M Dulick and Bauschlicher, {C W} and Bernath, {P F} and Ram, {R S} and Sharp, {C M} and Milsom, {J A}",

year = "2005",

month = may,

day = "10",

language = "English",

volume = "624",

pages = "988--1002",

journal = "The Astrophysical Journal",

issn = "1538-4357",

publisher = "IOP Publishing",

number = "2",

}

TY - JOUR

T1 - Spectroscopic constants, abundances, and opacities of the TiH molecule

AU - Burrows, A

AU - Dulick, M

AU - Bauschlicher, C W

AU - Bernath, P F

AU - Ram, R S

AU - Sharp, C M

AU - Milsom, J A

PY - 2005/5/10

Y1 - 2005/5/10

N2 - Using previous measurements and quantum chemical calculations to derive the molecular properties of the TiH molecule, we obtain new values for its rovibrational constants, thermochemical data, spectral line lists, line strengths, and absorption opacities. Furthermore, we calculate the abundance of TiH in M and L dwarf atmospheres and conclude that it is much higher than previously thought. We find that the TiH/TiO ratio increases strongly with decreasing metallicity, and at high temperatures can exceed unity. We suggest that, particularly for subdwarf L and M dwarfs, spectral features of TiH near &SIM; 0.52 and 0.94 μ m and in the H band may be more easily measurable than heretofore thought. The recent possible identification in the L subdwarf 2MASS J0532 of the 0.94 μ m feature of TiH is in keeping with this expectation. We speculate that looking for TiH in other dwarfs and subdwarfs will shed light on the distinctive titanium chemistry of the atmospheres of substellar-mass objects and the dimmest stars.

AB - Using previous measurements and quantum chemical calculations to derive the molecular properties of the TiH molecule, we obtain new values for its rovibrational constants, thermochemical data, spectral line lists, line strengths, and absorption opacities. Furthermore, we calculate the abundance of TiH in M and L dwarf atmospheres and conclude that it is much higher than previously thought. We find that the TiH/TiO ratio increases strongly with decreasing metallicity, and at high temperatures can exceed unity. We suggest that, particularly for subdwarf L and M dwarfs, spectral features of TiH near &SIM; 0.52 and 0.94 μ m and in the H band may be more easily measurable than heretofore thought. The recent possible identification in the L subdwarf 2MASS J0532 of the 0.94 μ m feature of TiH is in keeping with this expectation. We speculate that looking for TiH in other dwarfs and subdwarfs will shed light on the distinctive titanium chemistry of the atmospheres of substellar-mass objects and the dimmest stars.

KW - infrared : stars

KW - stars : atmospheres

KW - stars : fundamental parameters

KW - stars : low-mass, brown dwarfs

KW - subdwarfs

KW - TRANSITION-METAL HYDRIDES

KW - ALL-SKY SURVEY

KW - BROWN DWARF

KW - ROTATIONAL ANALYSIS

KW - DISCOVERY

KW - EQUILIBRIUM

KW - SPECTRUM

KW - STATES

KW - 2MASS

KW - CRH

M3 - Article

SN - 1538-4357

VL - 624

SP - 988

EP - 1002

JO - The Astrophysical Journal

JF - The Astrophysical Journal

IS - 2

ER -