On Age Spreads in Star-forming Regions

By L. Hartmann. 2001

164 citations recorded by the source corpus.

Subfields: Astronomy and Astrophysics, Spectroscopy

View Paper: https://www.semanticscholar.org/paper/08f69bc52c2579957be940429a273142cf7e4bb3

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Citations in the corpus

The Spitzer c2d Survey of Weak-Line T Tauri Stars. II. New Constraints on the Timescale for Planet Building (2007, background): “The age spreads derived are 2.2-3.2 times the value attributed by Hartmann (2001) to observational errors, which is also shown in Fig 13 for comparison.”
Near-Infrared Photometric Variability of Stars toward the Orion A Molecular Cloud (2001, background): “Only a small percentage of the stars should beM _a†ected in this manner, indicating that one must consider variability in interpreting the tails of mass and age distributions (see also Hartmann 2001).”
Pre-main-sequence isochrones - II. Revising star and planet formation time-scales (2013, background): “Secondly, the observed luminosity spread in CMD space, at a given colour, becomes more pronounced (see Hartmann 2001 for a discussion on the possible sources).”
On the mass function of star clusters (2002, background): “The figure shows the evolution of an embedded cluster with ǫ = 0.33 that expels its gas faster than a dynamical time after an embedded period lasting for 0.6 Myr (model A in KAH).”
Star formation in Perseus - Clusters, filaments and the conditions for star formation (2005, background): “The age spread of T Tauri populations is notoriously difficult to estimate from isochrones (Hartmann 2001), and the youngest IC 348 and NGC 1333 infrared members may well be less than 0.5 Myr old.”
Embedded Clusters in Molecular Clouds (2003, background): “…the significance of age spreads and distributions estimated from CMDs of embedded clusters because differential extinction, source variability, infrared excess, binarity, and contamination by field stars can contribute significantly to the intrinsic scatter in the diagram (e.g., Hartmann 2001).”
ALMA OBSERVATIONS OF CIRCUMSTELLAR DISKS IN THE UPPER SCORPIUS OB ASSOCIATION (2016, background): “In contrast, the mean age of stars in Taurus is ∼1-2 Myr based on HR diagram positions of member stars (Kenyon & Hartmann 1995; Hartmann 2001; Bertout et al. 2007; Andrews et al. 2013), indicating that Taurus is younger than Upper Sco.”
Modeling UV Radiation Feedback from Massive Stars. II. Dispersal of Star-forming Giant Molecular Clouds by Photoionization and Radiation Pressure (2018, background): “…populations in nearby star-forming clouds supports the picture that star-forming clouds are dispersed rapidly—on the cloud’s dynamical timescale (e.g. Hartmann 2001; Hartmann et al. 2001, but see also Da Rio et al. 2014, who argue that cluster formation takes several local dynamical timescales).”
Rapid Formation of Molecular Clouds and Stars in the Solar Neighborhood (2001, methodology): “Moreover, as emphasized by Hartmann (2001), the errors in placing stars in the HR or color-magnitude diagrams are sufficiently large that one should expect to find a few objects with spuriously large ages.”
A Census of the Chamaeleon I Star-forming Region (2004, background): “It is unclear whether a spread of ages is actually reflected in these data as the finite width of the sequence could also reflect extinction uncertainties, unresolved binaries, and variability from accretion and rotation of spotted surfaces (Kenyon & Hartmann 1990; Hartmann 2001).”
New Low-Mass Members of the Taurus Star-forming Region (2003, background): “…on the H-R diagram could arise not from a spread in ages but from various sources such as extinction uncertainties, unresolved binaries, variability from accretion and from rotation of spotted surfaces, and differences in distances to individual members (Kenyon & Hartmann 1990; Hartmann 2001).”
Stellar Rotation in Young Clusters: The First 4 Million Years (2004, methodology): “Similar analyses by Hartigan, Strom, & Strom (1994) and by Hartmann (2001) estimated the errors in R to be in the range 0.05–0.1 dex, with the larger errors applying to stars with high accretion rates, which may affect the colors and magnitudes, and to members of clusters that are extended along…”
A Census of the Young Cluster IC 348 (2003, background): “As a result, it is difficult to confidently measure star formation histories from H-R diagrams of star-forming regions (Kenyon & Hartmann 1990; Hartmann 2001), and it is unclear whether a spread of ages is actually reflected in the data for IC 348.”
Control of star formation by supersonic turbulence (2000, result): “Long periods of core formation for globally supported clouds appear consistent with the low efficiencies of star-formation in regions of isolated star formation, such as Taurus, even if they are rather young objects with ages of order τff .”
Dust properties of protoplanetary disks in the Taurus-Auriga star forming region from millimeter wavelengths (2009, background): “Hartmann (2001) has shown that the large age spread deduced for T Tauri stars in Taurus may just be the result of uncertainties in the measurements towards individual members of a population with a very narrow age spread.”
The Stellar Population of the Chamaeleon I Star-forming Region (2007, methodology): “I also account for binaries in the manner described by Hartmann (2001), except that I assume an unresolved binary fraction of 30%, which should be a reasonable value for a sample like the one in Chamaeleon I that is dominated by lowmass stars (Reid & Gizis 1997).”
The Initial Mass Function in the Taurus Star-forming Region (2002, background): “First, because these young populations are mostly coeval (Hartmann 2001), biases due to evolutionary effects, both stellar and dynamical, are minimized.”
Protoplanetary Disks and Their Evolution (2011, methodology): “…with model-derived stellar ages, it has been argued that individual star-forming regions lack the intrinsic age spread necessary to investigate disk lifetimes from individually derived ages and the apparent age dispersion is mostly driven by the observational uncertainties (Hartmann 2001).”
THE DISTANCE TO NGC 2264 (2009, background): “This estimate includes contributions from uncertainties in spectral type, 3 extinction values, and uncertainty due to source variability (Hartmann 2001).”