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Student Talks and 1 Slide Schedule
Wed., May 27
Studying the gamma-ray variability of the blazar 1ES 1215+303 - Floriana ZefiToggle Cloak Cloak We report on correlated variability from the BL Lac source 1ES 1215+303 detected by the spacebased Large Area Telescope, and VERITAS experiment. We studied the flux variability of the source in the energy range covered by FermiLAT (100 MeV < E < 100 GeV) from 56298 56424 MJD (JanuaryMay 2014). During this time period a huge flare was detected from the source, correlated with the flare observed by VERITAS experiment at even higher energies (E>100 GeV). In the preliminary results the source shows a hard spectrum for this time period with a spectral index of 1.84 +/ 0.06. The averaged integral flux in the 0.1100 GeV energy range is (8.19+/ 1.01)x10^8 ph/cm^2/s. From the oneday time bin light curve we estimated the variability time scale to be 4.41 h+/0.09. We use these results and the opacity argument to set a limit on the Doppler factor.
Fornax A - Jeff MagillToggle Cloak Cloak Prior to the launch of Fermi in 2008, the radio galaxy Fornax A was identified as one of the few extragalactic objects that might be detected as spatially extended above 100 MeV. However, even though it was detected with high confidence in the first 2 years of the mission, it was not determined to be an extended source. Recently, the Fermi-LAT collaboration developed a new event-level analysis called Pass 8 which yields a larger acceptance, a better angular and energy resolution, as well as smaller systematic uncertainties. The improvements provided with Pass 8 combined with a longer exposure means that the spatial extension of Fornax A is significantly detected, making it only the second extragalactic gamma-ray source so far to show extent. Details of this measurement will be presented along with modeling of the emission above 100 MeV.
The SpeedsterEXD A New EventTriggered Hybrid CMOS Xray Detector - Christopher GriffithToggle Cloak Cloak We present the characterization of a new event driven xray hybrid CMOS detector developed by Penn State University in collaboration with Teledyne Imaging Sensors. Hybrid CMOS detectors currently have many advantages over CCDs including lower susceptibility to radiation damage, lower power consumption, and faster readout time to avoid pileup. The SpeedsterEXD hybrid CMOS detector has many new features that improve upon the previous generation of detectors including two new inpixel features that reduce noise from known noise sources: (1) a lownoise, highgain CTIA amplifier to eliminate interpixel capacitance crosstalk and (2) inpixel CDS subtraction to reduce kTC noise. The most exciting new feature of the SpeedsterEXD is an inpixel comparator that enables read out of only the pixels that contain signal from an xray event. The user can set the comparator threshold so that only pixels with signal above the set threshold are read out. This comparator feature can increase effective frame rate by orders of magnitude. We present the read noise, dark current, interpixel capacitance, energy resolution, and gain variation measurements of two SpeedsterEXD detectors.
Indirect dark matter search in dwarf spheroidal galaxies - Niki KlopToggle Cloak Cloak Dwarf spheroidals are low luminosity satellite galaxies of the Milky Way which are highly dominated by dark matter. This makes them excellent candidates to search for signals from dark matter annihilation using gamma ray observations. I will discuss various aspects of my analysis of the Fermi-LAT data of several dwarf spheroidals and show my latest results.
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