Media

Galaxy Build-up at Cosmic Dawn: New Insights from Ultra-Deep Hubble and Spitzer Observations

Dr. Pascal Oesch Space Telescope Science Institute

Thanks to ultra-deep observations with the WFC3/IR camera on Hubble the frontier of galaxies has recently been pushed out to z~9-12, only ~450 Myr from the Big Bang. From several large Hubble programs such as the HUDF09, CANDELS, or CLASH, we were able to identify large samples of more than 200 galaxies at z~7-8, and we are now starting to build up the sample sizes of z~9-11 galaxy candidates. In particular, the recent HUDF12 campaign further increased the depth of the WFC3/IR dataset over the Hubble Ultra-Deep Field (HUDF), and enabled us to detect a sample of nine very faint z>8 galaxy candidates in the HUDF. Additionally, the newly completed CANDELS data over GOODS-North now revealed four relatively bright z~9-10 sources, which are in tension with the previous UV LF determination from the GOODS-South field, indicating that star-formation in the early universe might have been very stochastic. Using all z>8 candidates in and around both GOODS fields, we infer that the cosmic star-formation rate density in galaxies with SFR>0.7Msol/yr decreases rapidly at z>8, dropping by an order of magnitude from z~8 to z~10. With complementing, ultra-deep Spitzer IRAC data, we are additionally able to infer the stellar mass densities out to z~8-10. In this talk I will highlight recent progress in exploring the high redshift frontier and in understanding the growth of galaxies in the first two billion years. In particular, I will present current constraints on the UV luminosity function of galaxies at z>8, and I will demonstrate the power of combining deep Hubble and Spitzer data to directly track the star-formation and mass build-up of z>=4 galaxies.

 

 

In Pursuit of Dark Matter: Recent Results from the Super CDMS Program

Dr. Jodi Cooley Southern Methodist University

Davis Bottom: Living Memories // Isaac Hathaway Family and Education – Clip 2

Much of the contemporary history of Davis Bottom is found in the “living memories of residents. From August 2011 to February 2012, the production team conducted 14 oral history interviews with residents, former residents and community leaders as part of the Davis Bottom History Preservation Project. “I think oral history has a huge role in our consideration of the past,” says Dr. Kim McBride, Co-Director, Kentucky Archaeological Survey. “At a very general level, it provides a different source of data; often filling in gaps that we cannot reach using the standard documentary, history records such as tax records and deeds, and written histories, even diaries and letters. Related, but slightly different, is the fact that oral history also allows us to greatly increase the range of perspectives that can be brought into the conversation on the past.” The oral history interviews have been incorporated into the one-hour public television documentary, “Davis Bottom: Rare History, Valuable Lives” (KET). This one-hour documentary features comments from residents about growing up in Davis Bottom, the tight-knit nature of the neighborhood and the vital role of the community’s park. The original, unedited interviews were also compiled into the DVD “Davis Bottom: Living Memories” (3:39 hrs.), that has been provided to participants, local institutions and area archives. The oral history interviews are restricted for research and educational use only. Here are sample clips from each interview.

Davis Bottom: Living Memories // Isaac Hathaway Family and Education – Clip 3

Much of the contemporary history of Davis Bottom is found in the “living memories of residents. From August 2011 to February 2012, the production team conducted 14 oral history interviews with residents, former residents and community leaders as part of the Davis Bottom History Preservation Project. “I think oral history has a huge role in our consideration of the past,” says Dr. Kim McBride, Co-Director, Kentucky Archaeological Survey. “At a very general level, it provides a different source of data; often filling in gaps that we cannot reach using the standard documentary, history records such as tax records and deeds, and written histories, even diaries and letters. Related, but slightly different, is the fact that oral history also allows us to greatly increase the range of perspectives that can be brought into the conversation on the past.” The oral history interviews have been incorporated into the one-hour public television documentary, “Davis Bottom: Rare History, Valuable Lives” (KET). This one-hour documentary features comments from residents about growing up in Davis Bottom, the tight-knit nature of the neighborhood and the vital role of the community’s park. The original, unedited interviews were also compiled into the DVD “Davis Bottom: Living Memories” (3:39 hrs.), that has been provided to participants, local institutions and area archives. The oral history interviews are restricted for research and educational use only. Here are sample clips from each interview.

Davis Bottom: Living Memories // Isaac Hathaway Family and Education – Clip 1

Much of the contemporary history of Davis Bottom is found in the “living memories of residents. From August 2011 to February 2012, the production team conducted 14 oral history interviews with residents, former residents and community leaders as part of the Davis Bottom History Preservation Project. “I think oral history has a huge role in our consideration of the past,” says Dr. Kim McBride, Co-Director, Kentucky Archaeological Survey. “At a very general level, it provides a different source of data; often filling in gaps that we cannot reach using the standard documentary, history records such as tax records and deeds, and written histories, even diaries and letters. Related, but slightly different, is the fact that oral history also allows us to greatly increase the range of perspectives that can be brought into the conversation on the past.” The oral history interviews have been incorporated into the one-hour public television documentary, “Davis Bottom: Rare History, Valuable Lives” (KET). This one-hour documentary features comments from residents about growing up in Davis Bottom, the tight-knit nature of the neighborhood and the vital role of the community’s park. The original, unedited interviews were also compiled into the DVD “Davis Bottom: Living Memories” (3:39 hrs.), that has been provided to participants, local institutions and area archives. The oral history interviews are restricted for research and educational use only. Here are sample clips from each interview.

rrehle0's picture

A guide to Día de los muertos celebrations in Lexington

It’s a good weekend to be a hispanista in Lexington. Granted we’ve had a great fall; from the Lexington Latino Festival to the many activities surrounding the Arts and Sciences Passport ¡Viva México! program, those of us who love the Spanish language and Hispanic culture have been busy. Still, this Friday and Saturday are special. 

Controlled Magnetic Reversal and Emergent Metamagnetism in Permalloy Films Patterned into Artificial Quasicrystals

Dr. Lance Delong University of Kentucky

Ferromagnetic (FM) thin films patterned into periodic lattices of nanoscale holes or dots are candidated for UHD data storage media, an drelated wire network patterns are of fundamental interest as examples of controlled phase transitions in "artificial spin ice". Our recent Physical Review Letter reported an experimental study of the static and dynamic magnetic properties of FM permalloy thin films patterned as Penrose P2 (quasicrystal) tilings that exhibit long-range order, but aperiodic translational symmetry. Our DC magnetization and ferromagnetic resonance data constitute, we believe, the first experimental study of th espin wave dynamics of an artificial FM quasicrystalline thin film. Ground-breaking efforts were required to both pattern and deposit the sample film materials, and to execute large-scale numerical simulations of their static and dynamic behavior. This work demonstrates a new method for controlling the evolution of FM domain walls and spin wave spectra in magnetic media, in spite of a lack of periodic symmetry in an artificial quasicrystalline pattern. Simulations reveal a remarkably controlled sequence of reversals of individual film segments located on sublattices of the quasicrystal pattern, which may signal the occurence of true metamagnetic phase transitions in larger-area samples. These results directly imply FM films patterned as Penrose P2 tilings constitute a novel class of magnonic crystals whose magnon frequency dispersion and physical properties were heretofore unknown.

 

 

Two UK Students Named Astronaut Scholars

LEXINGTON, Ky. (Oct. 22, 2013) — Skylab astronaut Joe Kerwin will visit the University of Kentucky to present students Tyler "T.J." Flynn and Josiah Hanna each with a $10,000 scholarship from the Astronaut Scholarship Foundation (ASF) during a public lecture and ceremony, 5 p.m. Wednesday, Oct. 23, at the Engineering Commons, located in the Ralph G. Anderson Building.

For more information visit UKNOW: uknow.uky.edu/content/hall-fame-skylab-astronaut-honors-uk-students

Celebrate 2013

Dr. Pearl James, English Department

Pages

X
Enter your Earth and Environmental Sciences username.
Enter the password that accompanies your username.
Secure Login

This login is SSL protected

Loading