Search Results for author: Nicholas Battaglia

Found 16 papers, 8 papers with code

Augmenting astrophysical scaling relations with machine learning: application to reducing the Sunyaev-Zeldovich flux-mass scatter

1 code implementation4 Jan 2022 Digvijay Wadekar, Leander Thiele, Francisco Villaescusa-Navarro, J. Colin Hill, Miles Cranmer, David N. Spergel, Nicholas Battaglia, Daniel Anglés-Alcázar, Lars Hernquist, Shirley Ho

Using SR on the data from the IllustrisTNG hydrodynamical simulation, we find a new proxy for cluster mass which combines $Y_\mathrm{SZ}$ and concentration of ionized gas ($c_\mathrm{gas}$): $M \propto Y_\mathrm{conc}^{3/5} \equiv Y_\mathrm{SZ}^{3/5} (1-A\, c_\mathrm{gas})$.

Symbolic Regression

The Impacts of Modeling Choices on the Inference of the Circumgalactic Medium Properties from Sunyaev-Zeldovich Observations

no code implementations3 Mar 2021 Emily Moser, Stefania Amodeo, Nicholas Battaglia, Marcelo A. Alvarez, Simone Ferraro, Emmanuel Schaan

Finally, we show how different fitting models can reproduce parameters of a fiducial profile, and show that the addition of a two-halo term and matching by the mass distribution of the sample are extremely important modeling choices to consider.

Astrophysics of Galaxies

Constraining reionization with the first measurement of the cross-correlation between the CMB optical-depth fluctuations and the Compton y-map

no code implementations1 Feb 2021 Toshiya Namikawa, Anirban Roy, Blake D. Sherwin, Nicholas Battaglia, David N. Spergel

Since the power spectrum of the electron density fluctuations is constrained by the $\delta\tau$ auto spectrum, the temperature constraints should be only weakly model-dependent on the details of the electron distributions and should be statistically representative of the temperature in ionized bubbles during reionization.

PICO Cosmology and Nongalactic Astrophysics Astrophysics of Galaxies

Constraints on $f(R)$ and nDGP Modified Gravity Model Parameters with Cluster Abundances and Galaxy Clustering

no code implementations21 Jan 2021 Rayne Liu, Georgios Valogiannis, Nicholas Battaglia, Rachel Bean

For a fiducial model of $f(R)$ with $\text{log}_{10}(f_{R0})=-6$ and $n=1$ we find combined constraints of $\sigma(\text{log}_{10}(f_{R0}))=0. 48$ and $\sigma(n)=2. 3$, while for the nDGP model with $n_{\text{nDGP}}=1$ we find $\sigma(n_{\text{nDGP}})=0. 087$.

Cosmology and Nongalactic Astrophysics General Relativity and Quantum Cosmology

Multiwavelength cluster mass estimates and machine learning

no code implementations23 May 2019 J. D. Cohn, Nicholas Battaglia

One emerging application of machine learning methods is the inference of galaxy cluster masses.

Cosmology and Nongalactic Astrophysics

Fast Radio Burst Tomography of the Unseen Universe

no code implementations12 Mar 2019 Vikram Ravi, Nicholas Battaglia, Sarah Burke-Spolaor, Shami Chatterjee, James Cordes, Gregg Hallinan, Casey Law, T. Joseph W. Lazio, Kiyoshi Masui, Matthew McQuinn, Julian B. Munoz, Nipuni Palliyaguru, J. Xavier Prochaska, Andrew Seymour, Harish Vedantham, Yong Zheng

The discovery of Fast Radio Bursts (FRBs) at cosmological distances has opened a powerful window on otherwise unseen matter in the Universe.

High Energy Astrophysical Phenomena Astrophysics of Galaxies

Statistical properties of paired fixed fields

1 code implementation5 Jun 2018 Francisco Villaescusa-Navarro, Sigurd Naess, Shy Genel, Andrew Pontzen, Benjamin Wandelt, Lauren Anderson, Andreu Font-Ribera, Nicholas Battaglia, David N. Spergel

We quantify the statistical improvement brought by these simulations, over standard ones, on different power spectra such as matter, halos, CDM, gas, stars, black-holes and magnetic fields, finding that they can reduce their variance by factors as large as $10^6$.

Cosmology and Nongalactic Astrophysics Instrumentation and Methods for Astrophysics

A Machine Learning Approach for Dynamical Mass Measurements of Galaxy Clusters

no code implementations2 Oct 2014 Michelle Ntampaka, Hy Trac, Dougal J. Sutherland, Nicholas Battaglia, Barnabas Poczos, Jeff Schneider

In the conventional method, we use a standard M(sigma_v) power law scaling relation to infer cluster mass, M, from line-of-sight (LOS) galaxy velocity dispersion, sigma_v.

Cosmology and Nongalactic Astrophysics

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