Bulletin of the American Physical Society
2021 Joint Spring Meeting of the Texas Sections of APS, AAPT and Zone 13 of the SPS
Volume 66, Number 2
Thursday–Sunday, April 8–11, 2021; Virtual
Session C17: APS: Astrophysics and Space Science-III |
Hide Abstracts |
Saturday, April 10, 2021 2:00PM - 2:12PM |
C17.00001: Annihilation processes for a new dark matter WIMP Brandon Torres, Caden LaFontaine, Trevor Croteau, Bailey Tallman, Spencer Ellis, Sabrina Hernandez, Diego Cristancho Guerrero, Drue Lubanski, Roland Allen We propose a new dark matter WIMP which results from an extended Higgs sector, and which has only second-order gauge couplings. The coupling to the Higgs is constrained to be small by direct-detection experiments, and potential couplings to supersymmetric partners are also second-order. For this reason the annihilation cross-section is relatively small. Nevertheless, there would be inconsistency with both the observed relic abundance of the dark matter and the Fermi-LAT measurements of gamma-ray emissions from dwarf spheroidal galaxies if the mass of our proposed particle were larger than that of the W boson. We will discuss the annihilation processes for this particle, and contrast them with those for the neutralino of supersymmetry and the bosonic dark matter candidate of the \textit{ad hoc} ``inert doublet model''. [Preview Abstract] |
Saturday, April 10, 2021 2:12PM - 2:24PM |
C17.00002: Gravitational effects on oscillon lifetimes Hong-Yi Zhang Many scalar field theories with attractive self-interactions support exceptionally long-lived, spatially localized and time-periodic field configurations called oscillons. They can form naturally in the very early universe close to the big bang, or in dark matter in the present-day universe. To better understand their cosmological implications, it is crucial to study oscillon decay rates and lifetimes. In this short talk, I will first review such a method that can be applied to oscillons for generic potentials (including non-polynomial ones), and then discuss the gravitational effects on oscillon lifetimes. [Preview Abstract] |
Saturday, April 10, 2021 2:24PM - 2:36PM |
C17.00003: Chemical Abundance Analysis of Cetus II Kaitlin Webber, Terese Hansen, Jennifer Marshall Ultra-faint dwarf galaxies are low mass and luminosity galaxies that contain very metal poor stars. Abundance analysis of these stars provide insight to the early universe and galaxy evolution. We performed a chemical abundance analysis on the ultra-faint dwarf galaxy Cetus II. We derived abundances of one star in Cetus II from a high-resolution spectrum. The star has a low Magnesium abundance of [Mg/Fe]=0.07, while the calcium abundance of [Ca/Fe]=0.31 reflects the expected alpha-enhancement seen in metal-poor stars. A low Magnesium abundance with normal abundances for Calcium and other alpha elements signals that these elements were created by a star with a mass M $\lesssim$ 20 M$_\odot$. [Preview Abstract] |
Saturday, April 10, 2021 2:36PM - 2:48PM |
C17.00004: The Jet Stream In DELVE Peter Ferguson We are in an exciting era of Milky Way astronomy where many large survey datasets are helping to explore and understand the structure and substructure of our Galaxy. The DECam Local Volume Exploration (DELVE) survey is one such dataset. The first data release DELVE-DR1 provides photometric measurements of $\sim 520$ million astronomical sources covering $\sim 5,000 \mathrm{deg}^2$. We use this catalog to search for stellar streams around the Milky Way. Stellar streams are the results of tidal interactions between an infalling satellite galaxies/globular clusters and the Milky Way. They form long linear coherent structures spanning 10s of degrees across the sky. By identifying and characterizing these objects we can learn about the accretion history of our Galaxy, the gravitational potential in their vicinity, and probe for dark matter structures that may have perturbed the stream on small scales. In this talk I will discuss our results using photometry from DELVE and proper motions from $Gaia$ to characterize the Jet stream. Finding an extended length of the stream, and measuring for the first time a distance gradient, proper motion, and intensity variations along the stream. Adding jet to the population of well characterized stellar streams. [Preview Abstract] |
Follow Us |
Engage
Become an APS Member |
My APS
Renew Membership |
Information for |
About APSThe American Physical Society (APS) is a non-profit membership organization working to advance the knowledge of physics. |
© 2024 American Physical Society
| All rights reserved | Terms of Use
| Contact Us
Headquarters
1 Physics Ellipse, College Park, MD 20740-3844
(301) 209-3200
Editorial Office
100 Motor Pkwy, Suite 110, Hauppauge, NY 11788
(631) 591-4000
Office of Public Affairs
529 14th St NW, Suite 1050, Washington, D.C. 20045-2001
(202) 662-8700