We propose spectroscopic observations of the primary ISM cooling lines and the high-J CO ladder in a well-defined sample of nearby elliptical and lenticular galaxies. FIR line and line-continuum ratios will be used in conjunction with PDR models to constrain the physical conditions (gas density and strength of UV radiation field) in the ISM of these early-type galaxies. Similar work has been done extensively for spiral galaxies and (U)LIRGS but has only sporadically been done for quiescent ellipticals and lenticulars. We already have a broad suite of ancillary data for our targets, including HI and CO maps, high density molecular tracers, maps of the stellar populations (ages and metallicities) and optical emission lines. Our targets make an important bridge between normal star-forming spirals and cooling flow cluster galaxies, as they have some properties in common with both other types. Thus, this project is essential for placing other Herschel approved projects into the broader context of the interactions between gas and stars across the entire Hubble sequence.
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 , Probing the spectral shape of dust emission with the DustPedia galaxy sample . Nersesian Angelos et al. . Monthly Notices of the Royal Astronomical Society . null . null . 2021MNRAS.506.3986N , 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 Frédéric et al. . Astronomy and Astrophysics . null . null . 2021A&A...649A..18G , Dust emissivity and absorption cross section in DustPedia late-type galaxies . Bianchi S. et al. . Astronomy and Astrophysics . null . null . 2019A&A...631A.102B , Herschel Spectroscopy of Early-type Galaxies . Lapham Ryen Carl et al. . The Astrophysical Journal, Volume 840, Issue 1, article id. 51, 23 pp. (2017). . 840 . 10.3847/1538-4357/aa6d83 . 2017ApJ...840...51L , L‧CO-LFIR Relations with CO Rotational Ladders of Galaxies Across the Herschel SPIRE Archive . Kamenetzky J. et al. . The Astrophysical Journal, Volume 829, Issue 2, article id. 93, 16 pp. (2016). . 829 . 10.3847/0004-637X/829/2/93 . 2016ApJ...829...93K , 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. . Astro...nomy and Astrophysics . null . null . 2019A&A...624A..80N , 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 , UV to submillimetre luminosity functions of TNG50 galaxies . Trčka Ana et al. . Monthly Notices of the Royal Astronomical Society . null . null . 2022MNRAS.516.3728T , The Physical Characteristics of Interstellar Medium in NGC 3665 with Herschel Observations . Xiao Meng-Yuan et al. . The Astrophysical Journal, Volume 854, Issue 2, article id. 111, 12 pp. (2018). . 854 . 10.3847/1538-4357/aaa895 . 2018ApJ...854..111X , 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 ,
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.
