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SED Director's Seminar |
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June
10 |
SED Director's Seminar hosted by the Observational Cosmology Laboratory, Code 665! Nick Cothard - "Science and Detector Technology Development for the PRIMA Far-IR Probe Concept" The Probe far-Infrared Mission for Astrophysics (PRIMA) is a space-borne observatory that is being developed to answer the Astro 2020 Decadal's call for a potential far-infrared probe mission. In the 2030 decade, PRIMA is designed to address a vast range of astrophysics such as observations of the growth of stars, supermassive black holes, heavy elements, and dust over cosmic time, and observations of AGN feedback and interstellar medium physics in galaxies. To achieve these goals, we are developing superconducting kinetic inductance detectors (KIDs) and far-IR microlens array technologies. In this presentation, I will describe aspects of the science case for PRIMA and give an overview of recent developments in KIDs and optical coupling technologies. Chris DiLullo - "Observing the Global 21 cm Cosmic Dawn Signature with the Long Wavelength Array" The formation of the first stars, known as Cosmic Dawn, marks the beginning of a significant transition in the Universe's history. The light from the first stars drastically changes the astrophysics of the Universe during these times and plays a crucial role in determining how the earliest structures grow and evolve. The redshifted spectral signature of neutral hydrogen offers the strongest probe to study this epoch of cosmic history. Astrophysical models predict that a unique absorption signature, created by coupling between the neutral hydrogen and ultraviolet light from the first stars, exists in the average sky spectrum at frequencies below 100 MHz. The Experiment to Detect the Global EoR Signature (EDGES) collaboration reported the detection of such a signature with nonstandard spectral shape and amplitude (Bowman et al. 2018). If validated, the EDGES result would imply large deficits in our understanding of the early Universe and the first stars and galaxies. Therefore, an independent measurement must be made using another instrument which can properly validate the EDGES result. The Long Wavelength Array (LWA) located in New Mexico, USA offers excellent sensitivity and can observe in the necessary frequency band of 3-88 MHz. I will present ongoing work to use the LWA station located on the Sevilleta National Wildlife Refuge (LWA-SV) to validate the EDGES result. I will discuss novel observational and calibration strategies, present current limits, and discuss ideas to improve these limits in the future. Maryam Rahmani - Submillimeter and far-IR spectroscopy provides insight into galaxy evolution through measurement of atomic and molecular line emission. The EXperiment for Cryogenic Large-Aperture Intensity Mapping (EXCLAIM) is a cryogenic balloon-borne instrument designed to carry out intensity mapping to measure the cumulative redshifted line emission from carbon monoxide and singly-ionized carbon to probe star formation in windows from the present to z=3.5. During this time, the rate of star formation dropped dramatically, while dark matter continued to cluster. Intensity mapping permits a blind and complete survey of emitting gas through statistics of cumulative brightness fluctuations. EXCLAIM achieves high sensitivity using a cryogenic telescope coupled to six integrated spectrometers with spectral resolving power R=512 and employing microwave kinetic inductance detectors. Here we summarize the status of the mission.
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| Date | June 10, 2022 |
| Start/End Time | 12:00 PM - 01:00 PM |
| Location | Microsoft Teams |
| Contact | Ellie Jeffries |
| Email Address | ellen.e.jeffries@nasa.gov |
| Event Type | Seminars/Colloquia |
| Options | Add to my calendar. |
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