With its unprecedented spatial resolution in the critical 75-500 microns wavelength range, Herschel will provide a unique opportunity to determine, for the first time, the fundamental properties of the precursors of OB stars at distances out to a few kpc. The imaging speed of SPIRE and PACS in the parallel mode will enable us to map the entire extent of massive cloud complexes and detect the massive young stellar objects which have been overlooked by IRAS and Spitzer, i.e. the high-mass infrared-quiet protostars and pre-stellar cores.We propose to use SPIRE and PACS to image essentially all of the regions forming OB-type stars at distances < 3 kpc from the Sun (total area of 22~deg^2). To complement this imaging survey, we propose to take smaller photometric and spectroscopic maps with PACS toward a handful of isolated regions that display triggered star formation.The 75/110/170 micronsPACS and 250/350/500 microns SPIRE images of this project will provide an unbiased census of both massive pre-stellar cores and massive Class~0-like protostars, and will trace the large-scale emission of the surrounding clouds. This survey will yield for the first time accurate far-infrared photometry, and thus good luminosity and mass estimates, for a comprehensive, homogeneous sample of OB-type young stellar objects at all evolutionary stages. The multi-wavelength imaging will also reveal spatial variations of the cloud temperature close to HII regions and OB associations. These data, along with the detailed photometric and spectroscopic study of a few prototypical regions of induced star formation, will allow us to determine the importance of external triggers for high-mass star formation in the nearest massive molecular cloud complexes.This Herschel Key Programme is crucially needed to better understand the formation of OB-type stars and will provide the basis for many follow-up studies. In addition, the data will provide templates for galactic studies of star formation, both in our Galaxy and others.
Publication
Infrared emission and the destruction of dust in HII regions | Pavlyuchenkov Ya. N. et al. | Astronomy Reports Volume 57 Issue 8 pp.573-585 | 57 | 10.1134/S1063772913070056 | 2013ARep...57..573P | http://adsabs.harvard.edu/abs/2013ARep...57..573P
The dust properties of bubble H II regions as seen by Herschel | Anderson L. D. et al. | Astronomy & Astrophysics Volume 542 id.A10 27 pp. | 542 | 10.1051/0004-6361/201117283 | 2012A&A...542A..10A | http://adsabs.harvard.edu/abs/2012A%26A...542A..10A
Star formation triggered by the Galactic H II region RCW 120. First results from the Herschel Space Observatory | Zavagno A. et al. | Astronomy and Astrophysics Volume 518 id.L81 4 pp. | 518 | 10.1051/0004-6361/201014623 | 2010A&A...518L..81Z | http://adsabs.harvard.edu/abs/2010A%26A...518L..81Z
A Multi-band Catalog of 10978 Star Clusters Associations and Candidates in the Milky Way | Bica Eduardo et al. | The Astronomical Journal Volume 157 Issue 1 article id. 12 14 pp. (2019). | 157 | 10.3847/1538-3881/aaef8d | 2019AJ....157...12B | http://adsabs.harvard.edu/abs/2019AJ....157...12B
Star formation towards the Galactic H II region RCW 120. Herschel observations of compact sources | Figueira M. et al. | Astronomy & Astrophysics Volume 600 id.A93 27 pp. | 600 | 10.1051/0004-6361/201629379 | 2017A&A...600A..93F | http://adsabs.harvard.edu/abs/2017A%26A...600A..93F
Ionization compression impact on dense gas distribution and star formation. Probability density functions around H II regions as seen by Herschel | Tremblin P. et al. | Astronomy & Astrophysics Volume 564 id.A106 13 pp. | 564 | 10.1051/0004-6361/201322700 | 2014A&A...564A.106T | http://adsabs.harvard.edu/abs/2014A%26A...564A.106T
The physical properties of the dust in the RCW 120 H II region as seen by Herschel | Anderson L. D. et al. | Astronomy and Astrophysics Volume 518 id.L99 5 pp. | 518 | 10.1051/0004-6361/201014657 | 2010A&A...518L..99A | http://adsabs.harvard.edu/abs/2010A%26A...518L..99A
The warm-up phase in massive star-forming cores around RCW 120 | Kirsanova M. S. et al. | Monthly Notices of the Royal Astronomical Society | null | null | 2021MNRAS.503..633K |
APEX CO observations towards the photodissociation region of RCW 120 | Figueira M. et al. | Astronomy and Astrophysics | null | null | 2020A&A...639A..93F |
Herschel was launched on 14 May 2009! It is the fourth cornerstone mission in the ESA science programme. With a 3.5 m Cassegrain telescope it is the largest space telescope ever launched. It is performing photometry and spectroscopy in approximately the 55-671 µm range, bridging the gap between earlier infrared space missions and groundbased facilities.
European Space Agency, motte et al., 2010, 'HOBYS: the Herschel imaging survey of OB Young Stellar objects', SPG v14.2.0, European Space Agency, https://doi.org/10.5270/esa-z3tqu4h
