We propose to study the properties of dust in elliptical galaxies. The interstellar environment of elliptical galaxies is characterized by the dominance of hot plasma and old stellar radiation fields with little UV. Dust in hot plasma is easily destroyed by sputtering, while old stars cannot replenish a large amount of dust into the interstellar space. Despite such hostile conditions, many elliptical galaxies contain a considerable amount of dust.Our goals are to identify the supplying sources of dust and to understand interplay between dust and hot plasma. We selected 6 galaxies from the AKARI sample, which were found to be extended in the far-IR with AKARI. But its spatial resolution was too poor to discuss the detailed structures of the dust emission. Herschel is the only facility which enables us to discuss them. Our studies are based on two kinds of Herschel data: PACS imaging with the finest resolution and PACS-SPIRE SED mapping with a coarser resolution. Using the former data, we spatially decompose the dust distribution into a stellar distribution, a dust lane, a central point-like source, and the other. We derive the fraction of each component to the total emission. The last component may represent clumpy clouds in outer regions or structures extending from the center, which are compared with X-ray data. As for the latter data, we combine them with the AKARI mid-IR images to obtain SED maps. Each SED will be compared with model SEDs to investigate the dust size distribution and temperature. From spatial variations of the size distribution, we determine the dynamics of dust, i.e., in-falling to or out-flowing from the center of a galaxy. Finally the results of both studies will be combined to draw a firm conclusion on the origin of dust in elliptical galaxies.The proposed observations have exposure deep enough to detect diffuse emission associated with each galaxy, which are complementary to those so far performed with rather shallow exposure for a larger sample of elliptical 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
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 |
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
Instrument
PACS_PacsPhoto_largeScan, SPIRE_SpirePhoto_small
Temporal Coverage
2013-02-21T01:14:19Z/2013-04-26T15:23:09Z
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, kaneda et al., 2013, 'Spatially-resolved study of dust grains in X-ray elliptical galaxies \nto understand their origin and interplay with hot plasma', SPG v14.2.0, European Space Agency, https://doi.org/10.5270/esa-fij1lo7
