Abstract
We predict near-infrared luminosity functions of young (5 Myr to 1 Gyr) star clusters by combining evolutionary models of very low mass (1 M J to 0.15 M⊙) dwarfs with empirical bolometric corrections. We identify several characteristic features in our results. These can be attributed to three causes: (1) deuterium burning in the most massive substellar objects; (2) methane absorption in bodies with Teff less than 1300 K, the temperature of the L/T transition; and (3) the formation of dust clouds and the rainout of dust at roughly the same effective temperature as methane formation. Accurate reconstruction of the substellar mass function from luminosity function observations requires that these phenomena are taken into account. At present, few observational studies extend to sufficient sensitivities to allow detection of these effects. However, the luminosity function of the young open cluster IC 2391 shows a clear peak at MI ∼ 14, which we attribute to the result of deuterium burning in substellar objects. The location of this feature is a strong function of age, and we estimate an age of 35 Myr for IC 2391. This is significantly younger than the 53 Myr derived from the location of the lithium depletion boundary but agrees with the main-sequence turnoff age. We consider the implications of this result and our multiband luminosity functions for future observational studies. All predicted luminosity function features are, or will be, accessible to observations using new wide-field IR imagers and the Space Infrared Telescope Facility.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 1222-1230 |
| Number of pages | 9 |
| Journal | Astrophysical Journal |
| Volume | 595 |
| Issue number | 2 I |
| DOIs | |
| State | Published - Oct 1 2003 |
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Keywords
- Stars: evolution
- Stars: low-mass, brown dwarfs
- Stars: luminosity function, mass function
ASJC Scopus subject areas
- Space and Planetary Science
Cite this
Luminosity functions of young clusters : Modeling the substellar mass regime. / Allen, Peter R.; Trilling, David E; Koerner, David W; Reid, I. Neill.
In: Astrophysical Journal, Vol. 595, No. 2 I, 01.10.2003, p. 1222-1230.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Luminosity functions of young clusters
T2 - Modeling the substellar mass regime
AU - Allen, Peter R.
AU - Trilling, David E
AU - Koerner, David W
AU - Reid, I. Neill
PY - 2003/10/1
Y1 - 2003/10/1
N2 - We predict near-infrared luminosity functions of young (5 Myr to 1 Gyr) star clusters by combining evolutionary models of very low mass (1 M J to 0.15 M⊙) dwarfs with empirical bolometric corrections. We identify several characteristic features in our results. These can be attributed to three causes: (1) deuterium burning in the most massive substellar objects; (2) methane absorption in bodies with Teff less than 1300 K, the temperature of the L/T transition; and (3) the formation of dust clouds and the rainout of dust at roughly the same effective temperature as methane formation. Accurate reconstruction of the substellar mass function from luminosity function observations requires that these phenomena are taken into account. At present, few observational studies extend to sufficient sensitivities to allow detection of these effects. However, the luminosity function of the young open cluster IC 2391 shows a clear peak at MI ∼ 14, which we attribute to the result of deuterium burning in substellar objects. The location of this feature is a strong function of age, and we estimate an age of 35 Myr for IC 2391. This is significantly younger than the 53 Myr derived from the location of the lithium depletion boundary but agrees with the main-sequence turnoff age. We consider the implications of this result and our multiband luminosity functions for future observational studies. All predicted luminosity function features are, or will be, accessible to observations using new wide-field IR imagers and the Space Infrared Telescope Facility.
AB - We predict near-infrared luminosity functions of young (5 Myr to 1 Gyr) star clusters by combining evolutionary models of very low mass (1 M J to 0.15 M⊙) dwarfs with empirical bolometric corrections. We identify several characteristic features in our results. These can be attributed to three causes: (1) deuterium burning in the most massive substellar objects; (2) methane absorption in bodies with Teff less than 1300 K, the temperature of the L/T transition; and (3) the formation of dust clouds and the rainout of dust at roughly the same effective temperature as methane formation. Accurate reconstruction of the substellar mass function from luminosity function observations requires that these phenomena are taken into account. At present, few observational studies extend to sufficient sensitivities to allow detection of these effects. However, the luminosity function of the young open cluster IC 2391 shows a clear peak at MI ∼ 14, which we attribute to the result of deuterium burning in substellar objects. The location of this feature is a strong function of age, and we estimate an age of 35 Myr for IC 2391. This is significantly younger than the 53 Myr derived from the location of the lithium depletion boundary but agrees with the main-sequence turnoff age. We consider the implications of this result and our multiband luminosity functions for future observational studies. All predicted luminosity function features are, or will be, accessible to observations using new wide-field IR imagers and the Space Infrared Telescope Facility.
KW - Stars: evolution
KW - Stars: low-mass, brown dwarfs
KW - Stars: luminosity function, mass function
UR - http://www.scopus.com/inward/record.url?scp=0142168081&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0142168081&partnerID=8YFLogxK
U2 - 10.1086/377436
DO - 10.1086/377436
M3 - Article
VL - 595
SP - 1222
EP - 1230
JO - Astrophysical Journal
JF - Astrophysical Journal
SN - 0004-637X
IS - 2 I
ER -