Events
IPAC organizes and hosts a number of meetings and conferences.
IPAC hosts seminars every Wednesday from 12-1pm in IPAC's Large Conference Room (102) except where noted. Directions can be found on the visitor information page. Pizza and soda are available for purchase at a modest fee. Some weeks, the Time Domain Forum talk (which is not a lunch talk) is held on Thursday afternoons at 2:30 pm.
To receive seminar notification emails, you may sign up here. If you are interested in presenting a talk or seminar, please contact Peter Capak (Extragalactic), or Stephen Kane (Galactic/Solar System/Exoplanets). To present at the Time Domain Forum, contact Luisa Rebull.
Here is a partial list of astronomy-related talks in Pasadena:
- Caltech Astronomy Tea Talk (Mondays, 4pm)
- Caltech DPS Division Seminar (Mondays, 4pm)
- IR/sub-mm/mm Sack lunch series (Tuesdays, 12:15pm)
- Carnegie Colloquia series (Tuesdays, 4pm)
- Caltech Astronomy Colloquia (Wednesdays, 4pm)
- Caltech Physics Research Conference (Thursdays, 4pm)
- Carnegie Lunch Talk Series (Fridays, 12:15pm)
Special Note: For more astronomy related talks around Pasadena, check the following list maintained by IPAC scientist Solange Ramirez.
Wednesday, May 29, 2013
The remarkably small and compact sizes of massive quiescent galaxies at z~2 has fueled multiple studies that investigate different evolutionary scenarios to explain how these galaxies formed. A missing part of the puzzle is the nature of their progenitors. Such progenitors are expected to be massive, compact, star-forming galaxies at higher redshifts. However, direct evidence for such counterparts has proven difficult to obtain using only the HST optical images, which probe the rest-frame UV at redshifts z > 2. UV morphologies can easily miss large, massive, red hosts. Such camouflaged components would, however, be easily visible in the near-IR. Using the deepest HST WFC3/F160W imaging data from the CANDELS survey, that probes the optical rest-frame bands at z>2, in combination with NIR slitless spectroscopy from 3D-HST, we are able to identify a significant population of galaxies with similar structural properties as the quiescent population but without fully suppressed star-formation. The number density of these sources account for the observed increment in the density of massive quiescent galaxies between z=2 and 3, while their estimated luminosity-weighted ages are consistent with a formation epoch of ~1 Gyr. For some of these objects we detect prominent Balmer breaks and Balmer absorption lines that supports the post-starburst hypothesis. Interestingly enough, we also find a high rate of X-ray detections among these galaxies (> 40%) indicating that the triggering of an AGN could play a fundamental role in the quenching process.
