The spitzer c2d survey of weak-line t tauri stars. II. New constraints on the timescale for planet building

Lucas Cieza, Deborah L. Padgett, Karl R. Stapelfeldt, Jean Charles Augereau, Paul Harvey, Neal J. Evans, Bruno Merín, David Koerner, Anneila Sargent, Ewine F. Van Dishoeck, Lori Allen, Geoffrey Blake, Timothy Brooke, Nicholas Chapman, Tracy Huard, Shih Ping Lai, Lee Mundy, Philip C. Myers, William Spiesman, Zahed Wahhaj

Research output: Contribution to journalArticle

132 Scopus citations

Abstract

One of the central goals of the Spitzer Legacy Project "From Cores to Disks" (c2d) is to determine the frequency of circumstellar disks around weak-line T Tauri stars (WTTSs) and to study the properties and evolutionary status of these disks. Here we present a census of disks for a sample of over 230 WTTSs located in the c2d IRAC and MIPS maps of the Ophiuchus, Lupus, and Perseus Molecular Clouds. We find that ∼20% of the WTTSs in a magnitude-limited subsample have IR excesses at IRAC wavelengths. These disks frequencies are ∼3-6 times larger than that recently found for a sample of relatively isolated WTTSs located outside the highest extinction regions covered by the c2d maps. The disk fractions we find are more consistent with those obtained in recent Spitzer studies of WTTSs in young clusters such as IC 348 and Tr 37. According to their location in the H-R diagram, the WTTSs with excesses in our sample are among the younger part of the age distribution. Still, up to ∼50% of the apparently youngest stars in the sample show no evidence of IR excess, suggesting that the circumstellar disks of a sizable fraction of pre-main-sequence stars dissipate in a timescale of ∼1 Myr. We also find that none of the stars in our sample apparently older than ∼10 Myr have detectable circumstellar disks at wavelengths <24 μm. The WTTS disks in our sample exhibit a wide range of properties (SED morphology, inner radius, Ldisk/L*, etc.) that bridge the gaps observed between the CTTSs and the debris disk regimes.

Original languageEnglish (US)
Pages (from-to)308-328
Number of pages21
JournalAstrophysical Journal
Volume667
Issue number1 I
DOIs
StatePublished - Jan 1 2007
Externally publishedYes

Keywords

  • Infrared: stars
  • Open clusters and associations: individual (IC 348)
  • Planetary systems: protoplanetary disks
  • Stars: pre-main-sequence

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

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    Cieza, L., Padgett, D. L., Stapelfeldt, K. R., Augereau, J. C., Harvey, P., Evans, N. J., Merín, B., Koerner, D., Sargent, A., Van Dishoeck, E. F., Allen, L., Blake, G., Brooke, T., Chapman, N., Huard, T., Lai, S. P., Mundy, L., Myers, P. C., Spiesman, W., & Wahhaj, Z. (2007). The spitzer c2d survey of weak-line t tauri stars. II. New constraints on the timescale for planet building. Astrophysical Journal, 667(1 I), 308-328. https://doi.org/10.1086/520698