Disk evolution in the orion OBI association

Nuria Calvet, Cesar Briceño, Jesus Hernández, Sergio Hoyer, Lee Hartmann, Aurora Sicilia-Aguilar, S. T. Megeath, Paola D'Alessio

Research output: Contribution to journalArticle

52 Citations (Scopus)

Abstract

We analyze multiband photometry of a subsample of low-mass stars in the associations Ori OB1a and 1b discovered during the Centro de Investigaciones de Astronomía (CIDA) Orion Variability Survey, which have ages of 7-10 and 3-5 Myr, respectively. We obtained UBVR CI C photometry at Mount Hopkins for six classical T Tauri stars (CTTSs) and 26 weak T Tauri stars (WTTSs) in Ori OB1a and for 21 CTTSs and two WTTSs in Ori OB1b. We also obtained L-band photometry for 14 CTTSs at Mount Hopkins and 10 and 18 μm photometry with OSCIR at Gemini for six CTTSs; of these, all six were detected at 10 μm, whereas only one was detected at 18 μm. We estimate mass accretion rates from the excess luminosity at U and find that they are consistent with determinations for a number of other associations, with or without high-mass star formation. The observed decrease of mass accretion rate with age is qualitatively consistent with predictions of viscous evolution of accretion disks, although other factors can also play a role in slowing accretion rates. We compare the excesses over photospheric fluxes in H - K, K - L, and K - N with the younger sample of Taurus and find an overall decrease of disk emission from Taurus to Ori OB1b to Ori OB1a. This decrease implies that significant grain growth and settling toward the midplane has taken place in the inner disks of Ori OB1. We compare the spectral energy distribution of the star detected at both 10 and 18 μm with disk models for similar stellar and accretion parameters. We find that the low fluxes shortward of 18 μm of this Ori OB1b star cannot be due to the smaller disk radius expected from viscous evolution in the presence of the far-ultraviolet radiation fields from the OB stars in the association. Instead, we find that the disk of this star is essentially a flat disk, with little if any flaring, indicating a significant degree of dust settling toward the midplane, as expected from dust evolution in protoplanetary disks.

Original languageEnglish
Pages (from-to)935-946
Number of pages12
JournalAstronomical Journal
Volume129
Issue number2
DOIs
Publication statusPublished - Feb 2005

Fingerprint

T Tauri stars
accretion
photometry
stars
settling
dust
far ultraviolet radiation
ultraviolet radiation
protoplanetary disks
ultrahigh frequencies
spectral energy distribution
accretion disks
radiation distribution
star formation
luminosity
prediction
radii
energy
rate
estimates

Keywords

  • Accretion, accretion disks
  • Infrared: stars
  • Stars: formation
  • Stars: pre-main-sequence
  • Techniques: photometric

Cite this

Calvet, N., Briceño, C., Hernández, J., Hoyer, S., Hartmann, L., Sicilia-Aguilar, A., ... D'Alessio, P. (2005). Disk evolution in the orion OBI association. Astronomical Journal, 129(2), 935-946. https://doi.org/10.1086/426910
Calvet, Nuria ; Briceño, Cesar ; Hernández, Jesus ; Hoyer, Sergio ; Hartmann, Lee ; Sicilia-Aguilar, Aurora ; Megeath, S. T. ; D'Alessio, Paola. / Disk evolution in the orion OBI association. In: Astronomical Journal. 2005 ; Vol. 129, No. 2. pp. 935-946.
@article{3faf062d01714cc59d6123a2f5eb541f,
title = "Disk evolution in the orion OBI association",
abstract = "We analyze multiband photometry of a subsample of low-mass stars in the associations Ori OB1a and 1b discovered during the Centro de Investigaciones de Astronom{\'i}a (CIDA) Orion Variability Survey, which have ages of 7-10 and 3-5 Myr, respectively. We obtained UBVR CI C photometry at Mount Hopkins for six classical T Tauri stars (CTTSs) and 26 weak T Tauri stars (WTTSs) in Ori OB1a and for 21 CTTSs and two WTTSs in Ori OB1b. We also obtained L-band photometry for 14 CTTSs at Mount Hopkins and 10 and 18 μm photometry with OSCIR at Gemini for six CTTSs; of these, all six were detected at 10 μm, whereas only one was detected at 18 μm. We estimate mass accretion rates from the excess luminosity at U and find that they are consistent with determinations for a number of other associations, with or without high-mass star formation. The observed decrease of mass accretion rate with age is qualitatively consistent with predictions of viscous evolution of accretion disks, although other factors can also play a role in slowing accretion rates. We compare the excesses over photospheric fluxes in H - K, K - L, and K - N with the younger sample of Taurus and find an overall decrease of disk emission from Taurus to Ori OB1b to Ori OB1a. This decrease implies that significant grain growth and settling toward the midplane has taken place in the inner disks of Ori OB1. We compare the spectral energy distribution of the star detected at both 10 and 18 μm with disk models for similar stellar and accretion parameters. We find that the low fluxes shortward of 18 μm of this Ori OB1b star cannot be due to the smaller disk radius expected from viscous evolution in the presence of the far-ultraviolet radiation fields from the OB stars in the association. Instead, we find that the disk of this star is essentially a flat disk, with little if any flaring, indicating a significant degree of dust settling toward the midplane, as expected from dust evolution in protoplanetary disks.",
keywords = "Accretion, accretion disks, Infrared: stars, Stars: formation, Stars: pre-main-sequence, Techniques: photometric",
author = "Nuria Calvet and Cesar Brice{\~n}o and Jesus Hern{\'a}ndez and Sergio Hoyer and Lee Hartmann and Aurora Sicilia-Aguilar and Megeath, {S. T.} and Paola D'Alessio",
year = "2005",
month = "2",
doi = "10.1086/426910",
language = "English",
volume = "129",
pages = "935--946",
journal = "Astronomical Journal",
issn = "0004-6256",
publisher = "American Astronomical Society",
number = "2",

}

Calvet, N, Briceño, C, Hernández, J, Hoyer, S, Hartmann, L, Sicilia-Aguilar, A, Megeath, ST & D'Alessio, P 2005, 'Disk evolution in the orion OBI association', Astronomical Journal, vol. 129, no. 2, pp. 935-946. https://doi.org/10.1086/426910

Disk evolution in the orion OBI association. / Calvet, Nuria; Briceño, Cesar; Hernández, Jesus; Hoyer, Sergio; Hartmann, Lee; Sicilia-Aguilar, Aurora; Megeath, S. T.; D'Alessio, Paola.

In: Astronomical Journal, Vol. 129, No. 2, 02.2005, p. 935-946.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Disk evolution in the orion OBI association

AU - Calvet, Nuria

AU - Briceño, Cesar

AU - Hernández, Jesus

AU - Hoyer, Sergio

AU - Hartmann, Lee

AU - Sicilia-Aguilar, Aurora

AU - Megeath, S. T.

AU - D'Alessio, Paola

PY - 2005/2

Y1 - 2005/2

N2 - We analyze multiband photometry of a subsample of low-mass stars in the associations Ori OB1a and 1b discovered during the Centro de Investigaciones de Astronomía (CIDA) Orion Variability Survey, which have ages of 7-10 and 3-5 Myr, respectively. We obtained UBVR CI C photometry at Mount Hopkins for six classical T Tauri stars (CTTSs) and 26 weak T Tauri stars (WTTSs) in Ori OB1a and for 21 CTTSs and two WTTSs in Ori OB1b. We also obtained L-band photometry for 14 CTTSs at Mount Hopkins and 10 and 18 μm photometry with OSCIR at Gemini for six CTTSs; of these, all six were detected at 10 μm, whereas only one was detected at 18 μm. We estimate mass accretion rates from the excess luminosity at U and find that they are consistent with determinations for a number of other associations, with or without high-mass star formation. The observed decrease of mass accretion rate with age is qualitatively consistent with predictions of viscous evolution of accretion disks, although other factors can also play a role in slowing accretion rates. We compare the excesses over photospheric fluxes in H - K, K - L, and K - N with the younger sample of Taurus and find an overall decrease of disk emission from Taurus to Ori OB1b to Ori OB1a. This decrease implies that significant grain growth and settling toward the midplane has taken place in the inner disks of Ori OB1. We compare the spectral energy distribution of the star detected at both 10 and 18 μm with disk models for similar stellar and accretion parameters. We find that the low fluxes shortward of 18 μm of this Ori OB1b star cannot be due to the smaller disk radius expected from viscous evolution in the presence of the far-ultraviolet radiation fields from the OB stars in the association. Instead, we find that the disk of this star is essentially a flat disk, with little if any flaring, indicating a significant degree of dust settling toward the midplane, as expected from dust evolution in protoplanetary disks.

AB - We analyze multiband photometry of a subsample of low-mass stars in the associations Ori OB1a and 1b discovered during the Centro de Investigaciones de Astronomía (CIDA) Orion Variability Survey, which have ages of 7-10 and 3-5 Myr, respectively. We obtained UBVR CI C photometry at Mount Hopkins for six classical T Tauri stars (CTTSs) and 26 weak T Tauri stars (WTTSs) in Ori OB1a and for 21 CTTSs and two WTTSs in Ori OB1b. We also obtained L-band photometry for 14 CTTSs at Mount Hopkins and 10 and 18 μm photometry with OSCIR at Gemini for six CTTSs; of these, all six were detected at 10 μm, whereas only one was detected at 18 μm. We estimate mass accretion rates from the excess luminosity at U and find that they are consistent with determinations for a number of other associations, with or without high-mass star formation. The observed decrease of mass accretion rate with age is qualitatively consistent with predictions of viscous evolution of accretion disks, although other factors can also play a role in slowing accretion rates. We compare the excesses over photospheric fluxes in H - K, K - L, and K - N with the younger sample of Taurus and find an overall decrease of disk emission from Taurus to Ori OB1b to Ori OB1a. This decrease implies that significant grain growth and settling toward the midplane has taken place in the inner disks of Ori OB1. We compare the spectral energy distribution of the star detected at both 10 and 18 μm with disk models for similar stellar and accretion parameters. We find that the low fluxes shortward of 18 μm of this Ori OB1b star cannot be due to the smaller disk radius expected from viscous evolution in the presence of the far-ultraviolet radiation fields from the OB stars in the association. Instead, we find that the disk of this star is essentially a flat disk, with little if any flaring, indicating a significant degree of dust settling toward the midplane, as expected from dust evolution in protoplanetary disks.

KW - Accretion, accretion disks

KW - Infrared: stars

KW - Stars: formation

KW - Stars: pre-main-sequence

KW - Techniques: photometric

UR - http://www.scopus.com/inward/record.url?scp=15244351735&partnerID=8YFLogxK

U2 - 10.1086/426910

DO - 10.1086/426910

M3 - Article

AN - SCOPUS:15244351735

VL - 129

SP - 935

EP - 946

JO - Astronomical Journal

JF - Astronomical Journal

SN - 0004-6256

IS - 2

ER -

Calvet N, Briceño C, Hernández J, Hoyer S, Hartmann L, Sicilia-Aguilar A et al. Disk evolution in the orion OBI association. Astronomical Journal. 2005 Feb;129(2):935-946. https://doi.org/10.1086/426910