Hubble Space Telescope Imaging of the Post-Starburst Quasar UN 1025-0040: Evidence for Recent Star Formation
| Autor: | Wil van Breugel, B. J. Boyle, Alexei V. Filippenko, Gabriela Canalizo, Matthew Grabelsky, Tom Shanks, Scott M. Croom, Michael S. Brotherton |
|---|---|
| Rok vydání: | 2002 |
| Předmět: |
Physics
education.field_of_study Solar mass Active galactic nucleus Stellar population Star formation Astrophysics::High Energy Astrophysical Phenomena Population Astrophysics (astro-ph) FOS: Physical sciences Astronomy and Astrophysics Quasar Astrophysics Astrophysics::Cosmology and Extragalactic Astrophysics Galaxy Photometry (optics) Space and Planetary Science Astrophysics::Solar and Stellar Astrophysics Astrophysics::Earth and Planetary Astrophysics education Astrophysics::Galaxy Astrophysics |
| DOI: | 10.48550/arxiv.astro-ph/0203239 |
| Popis: | We present new Hubble Space Telescope (HST) WFPC2 images of the post-starburst quasar UN J1025-0040, which contains both an active galactic nucleus (AGN) and a 400-Myr-old nuclear starburst of similar bolometric luminosity (10^{11.6} solar luminosities). The F450W and F814W images resolve the AGN from the starburst and show that the bulk of the star light (6 x 10^{10} solar masses) is contained within a central radius of about 600 parsecs, and lacks clear morphological structures at this scale. Equating the point-source light in each image with the AGN contribution, we determined the ratio of AGN-to-starburst light. This ratio is 69% in the red F814W image, consistent with our previous spectral analysis, but about 50% in the blue F450W image whereas we had predicted 76%. The HST images are consistent with previous photometry, ruling out variability (a fading AGN) as a cause for this result. We can explain the new data if there is a previously unknown young stellar population present, 40 Myr or younger, with as much as 10% of the mass of the dominant 400-Myr-old population. This younger starburst may represent the trigger for the current nuclear activity. The multiple starburst ages seen in UN J1025-0040 and its companion galaxy indicate a complex interaction and star-formation history. Comment: 10 pages, 6 figures (3 in color), accepted by PASP |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|