Astronomy and Astrophysics – Astrophysics – Cosmology and Extragalactic Astrophysics
Scientific paper
2011-09-28
Astronomy and Astrophysics
Astrophysics
Cosmology and Extragalactic Astrophysics
40 pages, 17 figures, 8 tables, accepted by MNRAS (27/09/2011). A high resolution version of the paper can be found at http:
Scientific paper
We present the dust properties and star-formation histories of local submillimetre-selected galaxies in Herschel-ATLAS, classified by optical morphology. The early-type galaxies (ETGs) that are detected contain as much dust as typical spirals, and form a unique sample that has been blindly selected at submillimetre wavelengths. Comparing H-ATLAS galaxies to a control sample of optically selected galaxies, we find 5.5% of luminous ETGs are detected in H-ATLAS. The H-ATLAS ETGs contain a significant mass of cold dust: the mean dust mass is 5.5x10^7 Msun, with individual galaxies ranging from 9x10^5-4x10^8 Msun. This is comparable to that of spirals in our sample, and is an order of magnitude more dust than that found for the control ETGs, which have a median dust mass inferred from stacking of (0.8-4.0)x10^6 Msun. The ETGs detected in H-ATLAS have bluer NUV-r colours, higher specific star-formation rates and younger stellar populations than ETGs which are optically selected, and may be transitioning from the blue cloud to the red sequence. We also find that H-ATLAS and control ETGs inhabit similar low-density environments. We conclude that the dust in H-ATLAS and control ETGs cannot be solely from stellar sources, and a large contribution from dust formed in the ISM or external sources is required. Alternatively, dust destruction may not be as efficient as predicted. We also explore the properties of the most passive spiral galaxies in our sample with SSFR<10^-11/yr. We find these passive spirals have lower dust-to-stellar mass ratios, higher stellar masses and older stellar population ages than normal spirals. The passive spirals inhabit low density environments similar to those of the normal spiral galaxies in our sample. This shows that the processes which turn spirals passive do not occur solely in the intermediate density environments of group and cluster outskirts. (Abridged)
Baes Maarten
Bamford Steven P.
Bourne Nathan
Brough Sarah
Cava Antonio
No associations
LandOfFree
H-ATLAS/GAMA: Dusty early-type galaxies and passive spirals does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with H-ATLAS/GAMA: Dusty early-type galaxies and passive spirals, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and H-ATLAS/GAMA: Dusty early-type galaxies and passive spirals will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-44190