We propose deep PACS 100 and 160 micron imaging of three nearby,star-forming, low metallicity galaxies. These data will allow us tomake sensitive, high-resolution estimates of dust mass. We willcombine these measurements with our in-hand HI maps to measure thedust-to-gas ratio and estimate the molecular gas (H2) content in eachgalaxy. This is a challenging measurement that requires requires theresolution of PACS and good sensitivity, but H2 masses at lowmetallicity are very difficult to estimate by any other means. We willuse these H2 measurements to test recent models of H2 formation ingalaxies, improve the calibration of the CO-to-H2 conversion factor,and assess the efficiency of star formation from H2 at lowmetallicity. We will also be able to put constraints on the life cycleof dust at low metallicity from gradients in the dust-to-gasratio. These are all open questions that can best be addressed byobserving the molecular gas in low metallicity galaxies. Carrying outsuch an experiment outside the Local Group is necessary something thatonly Herschel can do.
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
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 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 |
Dust grain size evolution in local galaxies: a comparison between observations and simulations | Relano M. et al. | Monthly Notices of the Royal Astronomical Society | null | null | 2022MNRAS.515.5306R |
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 |
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
PACS_PacsPhoto_largeScan
Temporal Coverage
2011-07-03T17:57:58Z/2011-10-30T12:31:08Z
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.
European Space Agency, leroy et al., 2012, 'Dust-Based Molecular Gas Maps of Nearby Low-Metallicity Galaxies', SPG v14.2.0, European Space Agency, https://doi.org/10.5270/esa-mn3r3wr