| Name | OT2_smadde01_5 |
| Title | Star Formation and ISM properties in the lowest metal-poor galaxies observed by Herschel |
| URL | http://archives.esac.esa.int/hsa/whsa-tap-server/data?retrieval_type=OBSERVATION&observation_id=1342248295&instrument_name=PACS&product_level=LEVEL0&compress=true |
| DOI | https://doi.org/10.5270/esa-o2i73on |
| Author | European Space Agency |
| Description | A remarkable result to date is our recent SHINING detection of the [CII] line with PACS in the ultra-metal-poor galaxies: IZw18 and SBS0335-052 (1/40th and 1/50 solar metallicity) giving us the best opportunity to study the star formation and ISM properties under the most extreme metal-poor conditions we have in our local universe - conditions similar to primordial ISM at very high redshift. SBS0335-052 and IZw18 are the most metal-poor galaxies that will ever be observed by Herschel. In spite of similar metallicities, the 2 galaxies are very different in star formation rates and MIR and FIR luminosities, suggesting that metallicity is not the most important parameter controlling star formation activity. We ask here for complementary [OI] 63 mu m and [OIII] 88 mu m observations to be able to interpret the [CII] detection in terms of ionised and neutral gas properties. These galaxies are not detected in CO and we believe that the [CII] is probing the molecular gas not traced by CO - the .dark molecular gas. which could be a significant reservoir of fuel for the star formation in low metallicity galaxies. Our [CII] observations along with these followup lines, can provide a means to unveil this suspected reservoir of CO-free molecular gas. The [CII] detection along with these 10.2h of observations requested in this proposa, will shed unique, new insight on extremely low metallicity conditions for star formation and also help provide a standard calibration for getting a handle at the molecular gas reservoir in the high redshift lowest metallicity galaxies which will be a focus for ALMA studies. |
| Publication | The applicability of far-infrared fine-structure lines as star formation rate tracers over wide ranges of metallicities and galaxy types . De Looze Ilse et al. . Astronomy & Astrophysics, Volume 568, id.A62, 34 pp. . 568 . 10.1051\/0004-6361\/201322489 . 2014A&A...568A..62D , Diversity of dwarf galaxy IR-submm emission patterns: CLUES from hydrodynamical simulations . Santos-Santos Isabel M. E. et al. . Astronomy & Astrophysics, Volume 603, id.A4, 22 pp. . 603 . 10.1051\/0004-6361\/201629426 . 2017A&A...603A...4S , The Herschel Dwarf Galaxy Survey. I. Properties of the low-metallicity ISM from PACS spectroscopy . Cormier D. et al. . Astronomy & Astrophysics, Volume 578, id.A53, 53 pp. . 578 . 10.1051\/0004-6361\/201425207 . 2015A&A...578A..53C , Tracing the total molecular gas in galaxies: [CII] and the CO-dark gas . Madden S. C. et al. . Astronomy and Astrophysics . null . null . 2020A&A...643A.141M , The Herschel Dwarf Galaxy Survey. II. Physical conditions, origin of [C II] emission, and porosity of the multiphase low-metallicity ISM . Cormier D. et al. . Astronomy and Astrophysics . null . null . 2019A&A...626A..23C , Inferring the HII region escape fraction of ionizing photons from infrared emission lines in metal-poor star-forming dwarf galaxies . Ramambason L. et al. . Astronomy and Astrophysics . null . null . 2022A&A...667A..35R , |
| Instrument | PACS_PacsLineSpec_point |
| Temporal Coverage | 2012-07-16T05:03:54Z/2012-10-22T01:26:24Z |
| Version | SPG v14.2.0 |
| Mission Description | 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. |
| Creator Contact | https://support.cosmos.esa.int/h®erschel/ |
| Date Published | 2013-04-22T00:15:31Z |
| Publisher And Registrant | European Space Agency |
| Credit Guidelines | European Space Agency, 2013, Star Formation And Ism Properties In The Lowest Metal-Poor Galaxies Observed By Herschel, SPG v14.2.0, European Space Agency, https://doi.org/10.5270/esa-o2i73on |