A shallow though extensive H22.122-μm imaging survey of Taurus-Auriga-Perseus - I. NGC 1333, L1455, L1448 and B1

Abstract

We discuss wide-field near-infrared (near-IR) imaging of the NGC 1333, L1448, L1455 and B1 star-forming regions in Perseus. The observations have been extracted from a much larger narrow-band imaging survey of the Taurus-Auriga-Perseus complex. These H-2 2.122-mu m observations are complemented by broad-band K imaging, mid-IR imaging and photometry from the Spitzer Space Telescope, and published submillimetre CO J = 3-2 maps of high-velocity molecular outflows. We detect and label 85 H-2 features and associate these with 26 molecular outflows. Three are parsec-scale flows, with a mean flow lobe length exceeding 11.5 arcmin. 37 (44 per cent) of the detected H-2 features are associated with a known Herbig-Haro object, while 72 (46 per cent) of catalogued HH objects are detected in H-2 emission. Embedded Spitzer sources are identified for all but two of the 26 molecular outflows. These candidate outflow sources all have high near-to-mid-IR spectral indices (mean value of alpha similar to 1.4) as well as red IRAC 3.6-4.5 mu m and IRAC/MIPS 4.5-24.0 mu m colours: 80 per cent have [3.6]-[4.5] > 1.0 and [4.5]-[24] > 1.5. These criteria - high alpha and red [4.5]-[24] and [3.6]-[4.5] colours - are powerful discriminants when searching for molecular outflow sources. However, we find no correlation between alpha and flow length or opening angle, and the outflows appear randomly orientated in each region. The more massive clouds are associated with a greater number of outflows, which suggests that the star formation efficiency is roughly the same in each region.