Star formation and agn activity in interacting galaxies : A near-UV perspective
We study nearby galaxies in close pairs to study the key factors affecting star formation and active galactic nuclei (AGN) activity triggered during galaxy interactions. Close pairs are selected from the Sloan Digital Sky Survey assuming a projected separation of <30 kpc and recessional velocity difference <500 km s-1. Near-ultraviolet fluxes from GALEX are used to estimate specific star formation rates (SSFRs). We find a factor of ~5.3 increase in SSFR for low-mass (108-1011M⊙) close pair galaxies and a factor of ~2.1 increase in SSFR for highmass (1011-1013M⊙) close pairs compared to the general galaxy population. Considering galaxies of all masses, we find a factor of ~1.8 enhancement in SSFR for close pairs in field environments compared to non-pairs, with no significant increase for pairs in group and cluster environments. A modest decrease of a factor of ~1.4 is found in the Seyfert fraction in close pair galaxies when compared to isolated galaxies, which suggests that mergers may not trigger AGN activity at the close pair stage or may trigger a different class of AGN. This becomes a factor of ~4.2 decrease when we restrict our analysis to high-mass close pairs in group or cluster environments.
Published inMonthly Notices of the Royal Astronomical Society
MetadataShow full item record
Showing items related by title, author, creator and subject.
The H alpha galaxy survey. I. The galaxy sample, H alpha narrow-band observations and star formation parameters for 334 galaxies James, P.A.; Shane, N.S.; Beckman, J.E.; Cardwell, A.; Collins, C.A.; Etherton, J.; de Jong, R.S.; Fathi, K.; Knapen, J.; Peletier, R.F.; Percival, S.M.; Pollacco, D.L.; Seigar, M.S.; Stedman, S. (2004)We discuss the selection and observations of a large sample of nearby galaxies, which we are using to quantify the star formation activity in the local Universe. The sample consists of 334 galaxies across all Hubble types ...
On the Key Processes that Drive Galaxy Evolution: the Role of Galaxy Mergers, Accretion, Local Environment and Feedback in Shaping the Present-Day Universe Martin, Garreth (2019-07-17)The study of galaxy evolution is a fundamental discipline in modern astrophysics, dealing with how and why galaxies of all types evolve over time. The diversity of present-day galaxies is a reflection of the processes ...
The SCUBA-2 Cluster Snapshot Survey - I. Catalogue of lensed galaxies and submillimetre-bright central galaxies Cheale, R.~A.; Geach, J.~E.; Edge, A.~C.; Blain, A.~W.; Chapman, S.~C.; Egami, E.; Hogan, M.~T.; Rawle, T.~D.; Webb, T.~M.~A. (2019-04-01)The SCUBA-2 Cluster Snapshot Survey (S2CSS) observed 202 rich clusters of galaxies at 850 μm in relatively poor submillimetre observing conditions (τ225GHz>0.1) with the aim of identifying rare examples of bright (tens ...