Dr. Joshua Gundersen

Fall 2017 class: PHY 101
email: gunder@physics.miami.edu
voice: (305) 284 7115
Fax: (305) 284 4222
Rm 317, James L. Knight Physics Building
1320 Campo Sano Ave., Coral Gables, Fl. 33146

My research is focused on three main research topics; studies of the cosmic microwave background polarization, studies of the far infrared background, and astrophysical foreground characterization.

Cosmic Microwave Background Polarization - The cosmic microwave background (CMB) is the oldest light in the universe and it comes to us from the most distant regions of the universe. This light is a fossil remnant of the universe and it encodes significant amounts of information about the universe when it was much younger and simpler. In the process of quantifying various characteristics of this light (such as the spatial distribution and polarization), we are beginning to answer many age-old questions about the universe: How old is the universe? How did the universe begin, and will it one day end? What are the primary constituents of the universe? How did the various structures in the universe, such as galaxies and clusters, come to be? The Experimental Cosmology Group has been involved in the Cosmic Anisotropic Polarization Mapper (CAPMAP) and is currently involved in the Q/U Imaging ExperimenT (QUIET) that attempt to address these and many other questions.

Far Infrared Background - The far infrared background was discovered in 1999 by the Cosmic Background Explorer satellite. Unlike the CMB which comes from the Big Bang, this background is believed to be primary produced by an early generation of stars in the universe. These early stars were typically enshrouded in clouds of dust which absorbed and re-emitted the light in the form of heat (infrared radiation). This early generation of stars is primarily responsible for converting the primordial hydrogen and helium into the heavier elements such as carbon and oxygen which are fundamental to all things living. The Experimental Cosmolgy Group is involved in the BLAST experiment which detects this redshifted light at far infrared wavelengths from a high altitude balloon-borne platform. BLAST has had two successful science flights - one from Sweden to Canada in 2005 and another that traveled circumpolar around Antarctica in 2006. BLAST is currently being retrofitted for studies of polarized dust emission (see below).

Astrophysical Foreground Characterization - Astrophysical foregrounds pose a particular challenge for CMB polarization experiments. These foregrounds primarily come from polarized synchrotron radiation and dust emission from our own galaxy; however, there is another form of emission that is currently called the "anomalous emission" that has been detected by total intensity measurements at wavelengths of interest to CMB studies. There is great interest in figuring out what this "anomalous emission" comes from and whether it is polarized. This is one the main goals of the Ku-band Polarization Identifier (KUPID) experiment which is a follow on experiment to CAPMAP aimed at understanding the "anomalous emission". In addition there is not much known about the polarization properties of dust emission at millimeter and submillimeter wavelengths. One of the primary goals of an upgraded BLAST experiment, known as BLASTPol, is to study polarized dust emission at submillimeter wavelengths.

For more details see my web site.