Stephan.s Quintet (SQ) is an extensively studied compact group of galaxies, where tidal interactions have displaced large amounts of gas into the inter-galactic medium (IGM). Spitzer IRS observations revealed an extremely bright H2 line emission from warm molecular gas, coexisting with a giant (40 kpc), X-ray bright shock, attributed to a high-speed (1000 km/s) galaxy collision. The weakness of PAH and mid-IR dust continuum shows that the H2 gas is not associated with star formation (SF) in the shock, in sharp contrast with standard galaxies. Spitzer photometry suggests that most of the SF rather happens outside the center of the shock and galatic disks. Moreover, an extended FIR component, not connected with the galaxies, but coincident with the X-ray halo of the group, may have been revealed by MIPS, but its poor resolution make this identification difficult. This dust may contribute to cool the hot gas, and thus to fuel SF in the halo. In this context of understanding the processes that control SF in the group, we propose to map the thermal dust emission in all the PACS and SPIRE bands. This will allows for the first time to (1) estimate the total cold gas content in the IGM independently from our CO measurements, (2) make use of the Herschel high spatial resolution to separate the dust emission coming from SF regions, the shock, and the X-ray halo, in order to elucidate the origin of the dust emission in the group and its potential role in cooling the intra-cluster gas, and (3) compare the FIR SED in the different regions of the group to dust models in order to constrain the dust size distribution and the structure of the molecular gas. These observations, together with a companion spectroscopy proposal, will provide the missing pieces of the overall energetic bugdet of the main coolants of the galaxy collision. The results will have important consequences on our understanding of the energetics and the role of dust in high-redshift mergers, and in the formation of the first stars and galaxies.
Publication
DustPedia: Multiwavelength photometry and imagery of 875 nearby galaxies in 42 ultraviolet-microwave bands | Clark C. J. R. et al. | Astronomy & Astrophysics Volume 609 id.A37 30 pp. | 609 | 10.1051\\/0004-6361\\/201731419 | 2018A&A...609A..37C | http://adsabs.harvard.edu/abs/2018A%26A...609A..37C
Shock-enhanced C+ Emission and the Detection of H2O from the Stephan.s Quintet Group-wide Shock Using Herschel | Appleton P. N. et al. | The Astrophysical Journal Volume 777 Issue 1 article id. 66 16 pp. (2013). | 777 | 10.1088\\/0004-637X\\/777\\/1\\/66 | 2013ApJ...777...66A | http://adsabs.harvard.edu/abs/2013ApJ...777...66A
Infrared colours and spectral energy distributions of hard X-ray selected obscured and Compton-thick active galactic nuclei | Kilerci Eser Ece et al. | Monthly Notices of the Royal Astronomical Society | null | null | 2020MNRAS.494.5793K |
A nearby galaxy perspective on dust evolution. Scaling relations and constraints on the dust build-up in galaxies with the DustPedia and DGS samples | Galliano Frederic et al. | Astronomy and Astrophysics | null | null | 2021A&A...649A..18G |
Reproducing the Universe: a comparison between the EAGLE simulations and the nearby DustPedia galaxy sample | Trcka Ana et al. | Monthly Notices of the Royal Astronomical Society | null | null | 2020MNRAS.494.2823T |
Dust emissivity and absorption cross section in DustPedia late-type galaxies | Bianchi S. et al. | Astronomy and Astrophysics | null | null | 2019A&A...631A.102B |
DustPedia: the relationships between stars, gas, and dust for galaxies residing in different environments | Davies J. I. et al. | Astronomy and Astrophysics | null | null | 2019A&A...626A..63D |
Old and young stellar populations in DustPedia galaxies and their role in dust heating | Nersesian A. et al. | Astronomy and Astrophysics | null | null | 2019A&A...624A..80N |
BAT AGN Spectroscopic Survey. XI. The Covering Factor of Dust and Gas in Swift/BAT Active Galactic Nuclei | Ichikawa Kohei et al. | The Astrophysical Journal Volume 870 Issue 1 article id. 31 16 pp. (2019). | 870 | 10.3847\\/1538-4357\\/aaef8f | 2019ApJ...870...31I | http://adsabs.harvard.edu/abs/2019ApJ...870...31I
Fraction of bolometric luminosity absorbed by dust in DustPedia galaxies | Bianchi S. et al. | Astronomy & Astrophysics Volume 620 id.A112 21 pp. | 620 | 10.1051\\/0004-6361\\/201833699 | 2018A&A...620A.112B | http://adsabs.harvard.edu/abs/2018A%26A...620A.112B
UV to submillimetre luminosity functions of TNG50 galaxies | Trcka Ana et al. | Monthly Notices of the Royal Astronomical Society | null | null | 2022MNRAS.516.3728T |
Herschel observations of Hickson compact groups of galaxies: Unveiling the properties of cold dust | Bitsakis T. et al. | Astronomy & Astrophysics Volume 565 id.A25 31 pp. | 565 | 10.1051\\/0004-6361\\/201323349 | 2014A&A...565A..25B | http://adsabs.harvard.edu/abs/2014A%26A...565A..25B
DustPedia: A Definitive Study of Cosmic Dust in the Local Universe | Davies J. I. et al. | Publications of the Astronomical Society of the Pacific Volume 129 Issue 974 pp. 044102 (2017). | 129 | 10.1088\\/1538-3873\\/129\\/974\\/044102 | 2017PASP..129d4102D | http://adsabs.harvard.edu/abs/2017PASP..129d4102D
Dust emission profiles of DustPedia galaxies | Mosenkov A. V. et al. | Astronomy & Astrophysics Volume 622 id.A132 24 pp. | 622 | 10.1051\\/0004-6361\\/201833932 | 2019A&A...622A.132M | http://adsabs.harvard.edu/abs/2019A%26A...622A.132M
Instrument
SPIRE_SpirePhoto_small
Temporal Coverage
2011-05-08T22:18:51Z/2011-05-08T22:28:34Z
Version
SPG v14.1.0
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.
European Space Agency, guillard et al., 2011, 'Dust in shocks and star-forming regions outside galaxies: PACS and SPIRE photometry of Stephan.s Quintet', SPG v14.1.0, European Space Agency, https://doi.org/10.5270/esa-760h7vw
