Professor Puckett's Research Homepage

Joyce Caliendo, University of Connecticut


Early Science with the Large Millimeter Telescope: Constraining the Gas Fraction of a Compact Quiescent Galaxy at z = 1.883


We present constraints on the dust continuum flux and inferred gas content of a gravitationally lensed massive quiescent galaxy at z=1.883 +/- 0.001 using AzTEC 1.1mm imaging with the Large Millimeter Telescope. MRG-S0851 appears to be a prototypical massive compact quiescent galaxy but has evidence that it experienced a centrally concentrated rejuvenation event in the last 100 Myr. This galaxy is undetected in the AzTEC image but we calculate an upper limit on the millimeter flux and use this to estimate the H_2 mass limit via an empirically calibrated relation that assumes a constant molecular gas-to-dust ratio of 150.

We constrain the 3 sigma upper limit of the H_2 fraction from the dust continuum in MRG-S0851 to be M_(H_2)/M_* < 6.8%. MRG-S0851 has a low gas fraction limit with a moderately low sSFR owing to the recent rejuvenation episode, which together results in a relatively short depletion time of

Dr. Siddharth Mohite, UW-Milwaukee and CCA, Flatiron Institute


Investigating Populations across the Gravitational-Wave Mass Spectrum: Statistical Tools and Implications for Astrophysics



Merging compact object binaries comprising of pairs of black holes, neutron stars or a neutron star and a black hole are energetic sources of gravitational-wave (GW) and electromagnetic (EM) radiation. Current and future gravitational-wave observatories such as LIGO-Virgo-KAGRA, LISA and NANOGrav will help uncover a diverse population of these binaries across the mass spectrum. While the LIGO-Virgo-KAGRA observatories probe compact objects roughly from 1 to 100 times a solar mass, observatories such as LISA and NANOGrav are predicted to probe supermassive binaries in the million to billion solar mass regimes. On the other hand, telescopes around the world will aid in detecting binaries that contain neutron stars by observing an associated electromagnetic counterpart called a kilonova. Investigating the properties of these binary populations will shed light on some long-standing problems in astrophysics such as stellar and galaxy evolution and nuclear equation of state. In this talk, I will present an attempt to create a Bayesian framework that can simultaneously use information from GW and EM surveys to place constraints on the kilonova population. I will also briefly introduce a method to model the mass distribution of binaries detectable by LIGO-Virgo-KAGRA, using Gaussian processes. Finally, I will also present some investigations into modeling the effects of circum-binary gas and eccentricity on the expected gravitational-wave sources from merging supermassive black hole binaries detectable by observatories like NANOGrav.

Professor Philip Mannheim
University of Connecticut
Physics Department Colloquium Series

Title: Quantum mechanics off the beaten track

Abstract: We discuss some non-conventional options for quantum theory.
We show that not only do Hamiltonians not need
to be Hermitian to have real eigenvalues, they do not even need to be
diagonalizable or possess a complete spectrum of energy eigenstates. We
discuss how to formulate quantum mechanics in such cases.
We show that
it is not always possible to write the momentum operator as the familiar
derivative operator $-id/dx$ where x is real, and discuss what one should
then do. Following
work by Bender and Mannheim [Phys. Rev. Lett. 100, 110402 (2008)] we show
how these issues are relevant to the construction of a consistent theory
of quantum gravity in four spacetime dimensions. In this theory there is no observable graviton.