A Spitzer Census of the IC 348 Nebula

By August Muench, C. Lada, K. Luhman, J. Muzerolle, E. Young. 2007

139 citations recorded by the source corpus.

Spitzer mid-infrared surveys enable an accurate census of young stellar objects by sampling large spatial scales, revealing very embedded protostars, and detecting low-luminosity objects. Taking advantage of these capabilities, we present a Spitzer-based census of the IC 348 nebula and embedded star cluster, covering a 2.5 pc region and comparable in extent to the Orion Nebula. Our Spitzer census supplemented with ground-based spectra has added 42 Class II T Tauri sources to the cluster membership and identified ∼20 Class 0/I protostars. The population of IC 348 likely exceeds 400 sources after accounting statistically for unidentified diskless members. Our Spitzer census of IC 348 reveals a population of Class I protostars that is anticorrelated spatially with the Class II/III T Tauri members, which comprise the centrally condensed cluster around a B star. The protostars are instead found mostly at the cluster periphery about ∼1 pc from the B star and spread out along a filamentary ridge. We further find that the star formation rate in this protostellar ridge is consistent with that rate which built the older exposed cluster, while the presence of 15 cold, starless, millimeter cores intermingled with this protostellar population indicates that the IC 348 nebula has yet to finish forming stars. Moreover, we show that the IC 348 cluster is of order 3-5 crossing times old, and, as evidenced by its smooth radial profile and confirmed mass segregation, is likely relaxed. While it seems apparent that the current cluster configuration is the result of dynamical evolution and its primordial structure has been erased, our finding of a filamentary ridge of Class I protostars supports a model in which embedded clusters are built up from numerous smaller subclusters. Finally, the results of our Spitzer census indicate that the supposition that star formation must progress rapidly in a dark cloud should not preclude these observations that show it can be relatively long lived.

Subfields: Astronomy and Astrophysics, Spectroscopy

View Paper: https://www.semanticscholar.org/paper/c3c4273cf6c078b0074f06181d612cfdca85e0d2

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

1. K. Luhman
2. P. Myers
3. N. Evans II
4. L. Hillenbrand
5. Michael C. Liu
6. Eric Mamajek
7. L. Allen
8. L. Hartmann

In Spectroscopy

1. K. Luhman
2. P. Myers
3. N. Evans II
4. L. Allen
5. R. Gutermuth
6. L. Hartmann
7. P. R. Allen
8. L. Hillenbrand

Citations in the corpus

• FILAMENTARY STRUCTURE OF STAR-FORMING COMPLEXES (2009, methodology): “This time is 3.0 Myr for the large-scale spacing 5.0 pc in Figures 17 and 20, whereas the free fall time of the same system is everywhere less than 2.4 Myr.”
• A CORRELATION BETWEEN SURFACE DENSITIES OF YOUNG STELLAR OBJECTS AND GAS IN EIGHT NEARBY MOLECULAR CLOUDS (2011, background): “The observations that spatially proximate prestellar cores are likely formed with low relative velocities (Walsh et al. 2007; Muench et al. 2007) suggest that the typical velocity dispersion of of the YSOs that emerge from the cores is small (∼0.4 km s−1).”
• SpeX SPECTROSCOPY OF UNRESOLVED VERY LOW MASS BINARIES. I. IDENTIFICATION OF 17 CANDIDATE BINARIES STRADDLING THE L DWARF/T DWARF TRANSITION (2009, methodology): “An initial sample was constructed by excluding known binaries (Burgasser et al. 2007b and references therein) young cluster objects (e.g., Muench et al. 2007), and sources specifically noted to have peculiar spectra associated with low surface gravities, subsolar metallicites or unusual cloud…”
• ON THE STAR FORMATION RATES IN MOLECULAR CLOUDS (2010, background): “The median mass for the IMF of a stellar population is 0.5 M⊙ (e.g., Muench et al. 2007).”
• A SPITZER SURVEY OF YOUNG STELLAR CLUSTERS WITHIN ONE KILOPARSEC OF THE SUN: CLUSTER CORE EXTRACTION AND BASIC STRUCTURAL ANALYSIS (2009, methodology): “…wavelength reflection and midinfrared PAH feature nebulosities, we can consider IC 348 Core-1 and the IC 5146 Core to be regions where local star formation has recently ceased (this assumption is supported in IC 348 by the detailed star formation history analysis presented in Muench et al. 2007).”
• THE DISK POPULATION OF THE TAURUS STAR-FORMING REGION (2009, methodology): “The Spitzer measurements and extinction estimates are from Lada et al. (2006), Muench et al. (2007), and Currie et al. (2009b) and the Ks data are from 2MASS.”
• The Disk Population of the Chamaeleon I Star-forming Region (2008, background): “…Taurus (Hartmann et al. 2005; Luhman et al. 2006; Guieu et al. 2007), Perseus (Luhman et al. 2005b; Lada et al. 2006; Jørgensen et al. 2006; Muench et al. 2007; Rebull et al. 2007; Gutermuth et al. 2007), Lupus (Allen et al. 2007), Serpens (Harvey et al. 2006, 2007; Winston et al. 2007),…”
• The Formation and Early Evolution of Low-Mass Stars and Brown Dwarfs (2012, methodology): “The ability of the Spitzer Space Telescope (Werner et al. 2004) to collect sensitive, wide-field mid-IR images has made it possible to apply this technique on a much larger scale (Allers et al. 2007, Luhman et al. 2009b, 2006, Muench et al. 2007, Rebull et al. 2010).”
• The Stellar Populations of Praesepe and Coma Berenices (2007, background): “…formation, stellar structure, stellar multiplicity, and circumstellar processes like planet formation (e.g., Patience et al. 2002; Bouy et al. 2006; Muench et al. 2007; Stauffer et al. 2007; Siegler et al. 2007); star clusters are uniquely sensitive to the physics of these processes due to their…”
• AN INFRARED/X-RAY SURVEY FOR NEW MEMBERS OF THE TAURUS STAR-FORMING REGION (2009, methodology): “The SED of KPNO 5 consists of data from 2MASS, SpeX (Muench et al. 2007), and Spitzer (Luhman et al. 2009b) and has been reddened by AJ = 7.3 to match the reddening of 2M 0419+2712 (KPNO 5 has AJ ∼ 0.3).”
• THE SPITZER SPACE TELESCOPE SURVEY OF THE ORION A AND B MOLECULAR CLOUDS. I. A CENSUS OF DUSTY YOUNG STELLAR OBJECTS AND A STUDY OF THEIR MID-INFRARED VARIABILITY (2012, background): “…excesses from dusty disks and envelopes is now well established in the literature (e.g., Allen et al. 2004, 2007; Megeath et al. 2004; Gutermuth et al. 2004, 2008; Muzerolle et al. 2004; Whitney et al. 2004; Hartmann et al. 2005; Winston et al. 2007; Muench et al. 2007; Robitaille et al. 2007).”
• THE SPITZER c2d LEGACY RESULTS: STAR-FORMATION RATES AND EFFICIENCIES; EVOLUTION AND LIFETIMES (2008, background): “These estimates include Spitzer data on embedded sources and the analysis of the age spread of the IC348 cluster from Muench et al. (2007).”