Published in MNRAS, 2020
A short time ago (about 500 – 1000 years), in a galaxy very nearby (our own Milky Way, in fact), something fascinating happened in the Orion Nebula. If only humans had evolved and developed astronomy on a slightly faster schedule, we might have witnessed this event. Regrettably, we procrastinated for several hundred years in the Middle Ages, and missed the show. All we can see is the aftermath, known as the Orion fingers.
Published in JHEP, 2020
The Schwarzschild black hole is “like” a point charge. It’s a mass localized at the origin which sources a field ($h_{\mu\nu} \equiv g_{\mu\nu}-\eta_{\mu\nu}$) which decays as $\frac{1}{r}$, just like a point charge is a charge localized at the origin which sources a field ($A_\mu$) which decays as $\frac{1}{r}$. Is there a precise way in which these two objects are related? In fact, yes: in 2014, Monteiro et al. presented the Kerr-Schild double copy, which provides a prescription for taking certain stationary solutions to the Einstein equations and writing them as “squares” of solutions to the Maxwell equations.
Published in MNRAS, 2019
As part of the Sloan Digital Sky Survey, the MaNGA (Mapping Nearby Galaxies at APO) project is producing a catalog of integral field unit (IFU) spectra of nearby galaxies. IFU spectra provide detailed information about the light coming from different points in a galaxy. This is an invaluable tool for astronomy, and in particular, when these galaxies are hosts of Type II quasars, the IFU spectra can be used to calculate the [O III] size and luminosity, the quantities we modeled here. This paper uses MaNGA data to add many more points to the observed size/luminosity relationship, and among many other things, addresses whether that model holds water.
Published in MNRAS, 2018
In some distant galaxies – many of them so distant that the light we see from them was emitted some 10 billion years ago – a supermassive black hole, containing the mass of millions or billions of Suns, is surrounded by a disk of gas. As this gas falls into the black hole, its energy is converted into radiation across the electromagnetic spectrum, forming an extraordinarily luminous object known as a quasar. Quasars are so luminous that they can outshine entire galaxies, and thus they are a force to be reckoned with in their own host galaxies. Astronomers studying galaxy formation are particularly interested in how they formation of a quasar can lead to feedback on the host galaxy, whereby the quasar is so powerful that it blows away gas in the galaxy and diminishes the formation of more stars.
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