Star Formation Across the W3 Complex

Author(s)

Carlos G. Román-Zúñiga, Jason E. Ybarra, Guillermo D. Megías, Mauricio Tapia, Elizabeth A. Lada, Joáo F. Alves

Abstract

We present a multi-wavelength analysis of the history of star formation

in the W3 complex. Using deep, near-infrared ground-based images

combined with images obtained with Spitzer and Chandra observatories, we

identified and classified young embedded sources. We identified the

principal clusters in the complex and determined their structure and

extension. We constructed extinction-limited samples for five principal

clusters and constructed K-band luminosity functions that we compare

with those of artificial clusters with varying ages. This analysis

provided mean ages and possible age spreads for the clusters. We found

that IC 1795, the centermost cluster of the complex, still hosts a large

fraction of young sources with circumstellar disks. This indicates that

star formation was active in IC 1795 as recently as 2 Myr ago,

simultaneous to the star-forming activity in the flanking embedded

clusters, W3-Main and W3(OH). A comparison with carbon monoxide emission

maps indicates strong velocity gradients in the gas clumps hosting

W3-Main and W3(OH) and shows small receding clumps of gas at IC 1795,

suggestive of rapid gas removal (faster than the T Tauri timescale) in

the cluster-forming regions. We discuss one possible scenario for the

progression of cluster formation in the W3 complex. We propose that

early processes of gas collapse in the main structure of the complex

could have defined the progression of cluster formation across the

complex with relatively small age differences from one group to another.

However, triggering effects could act as catalysts for enhanced

efficiency of formation at a local level, in agreement with previous

studies.

Organisation(s)

Department of Astrophysics

External organisation(s)

Universidad Nacional Autonoma de Mexico, Universidad de Sevilla, University of Florida, Gainesville

Journal

The Astronomical Journal

Volume

150

No. of pages

Publication date

09-2015

Peer reviewed

Yes

Austrian Fields of Science 2012

103003 Astronomy, 103004 Astrophysics

Keywords

ASJC Scopus subject areas

Astronomy and Astrophysics, Space and Planetary Science

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