Whitcomb, Cory M. Smith, J.-D. T. Sandstrom, Karin Starkey, Carl A. Donnelly, Grant P. Draine, Bruce T. Skillman, Evan D. Dale, Daniel A. Armus, Lee Hensley, Brandon S.
...
Published in
The Astrophysical Journal
We use deep Spitzer mid-infrared spectroscopic maps of radial strips across three nearby galaxies with well-studied metallicity gradients (M101, NGC 628, and NGC 2403) to explore the physical origins of the observed deficit of polycyclic aromatic hydrocarbons (PAHs) at subsolar metallicity (i.e., the PAH–metallicity relation or PZR). These maps all...
Shaik, Aamil Meyer, Eileen T. Reddy, Karthik Laha, Sibasish Georganopoulos, Markos
Published in
The Astrophysical Journal
The origin of X-ray emission from the resolved kiloparsec-scale jets and hotspots of many active galactic nuclei remains uncertain, particularly where the X-ray emission is separate from the radio-optical synchrotron component. Possible explanations include synchrotron emission from a second electron population and external Compton or synchrotron s...
Kurian, Kshama Sara Stalin, C. S. Wylezalek, Dominika Lyubenova, Mariya Adhikari, Tek Prasad Devaraj, Ashish Sagar, Ram Kissler-Patig, Markus Mondal, Santanu
Published in
The Astrophysical Journal
Active galactic nuclei (AGN) feedback and its impact on their host galaxies are critical to our understanding of galaxy evolution. Here, we present a combined analysis of new high resolution ultraviolet (UV) data from the Ultraviolet Imaging Telescope (UVIT) on AstroSat and archival optical spectroscopic data from the Very Large Telescope/MUSE, for...
Sanchez, Adonis A. Reines, Amy E. Bogdán, Ákos Kraft, Ralph P.
Published in
The Astrophysical Journal
The ability to accurately discern active massive black holes (BHs) in nearby dwarf galaxies is paramount to understanding the origins and processes of “seed” BHs in the early Universe. We present Chandra X-ray Observatory observations of a sample of three local dwarf galaxies (M * ≤ 3 × 109 M ⊙, z ≤ 0.15) previously identified as candidates for hos...
Thiersen, Hannes Zacharias, Michael Böttcher, Markus
Published in
The Astrophysical Journal
Blazars exhibit multiwavelength variability, a phenomenon whose underlying mechanisms remain elusive. This study investigates the origin of such variability through leptonic blazar emission simulations, focusing on stochastic fluctuations in environmental parameters. By analyzing the spectral indices of the power spectral densities of the variabili...
Spitzer, Sarah A. Lepri, Susan T. Raines, Jim M. Gilbert, Jason A. Bower, Jonathan Dewey, Ryan M. Möbius, Eberhard
Published in
The Astrophysical Journal
The size, shape, and composition of the heliosphere are affected by its interaction with the local interstellar medium. A means of quantifying this interaction is by measuring the relative motion of the two media. We determine the flow direction, λISN , of the interstellar wind through the heliosphere and its trend over an 11 yr solar cycle using A...
Bandopadhyay, Ananya Coughlin, Eric R. Nixon, C. J. Pasham, Dheeraj R.
Published in
The Astrophysical Journal
Some electromagnetic outbursts from the nuclei of distant galaxies have been found to repeat on months-to-years timescales, and each of these sources can putatively arise from the accretion flares generated through the repeated tidal stripping of a star on a bound orbit about a supermassive black hole (SMBH), i.e., a repeating partial tidal disrupt...
Vashishth, Vindya Karak, Bidya Binay
Published in
The Astrophysical Journal
Meridional flow is crucial in generating the solar poloidal magnetic field by facilitating poleward transport of the field from decayed bipolar magnetic regions (BMRs). As the meridional circulation changes with the stellar rotation rate, the properties of stellar magnetic cycles are expected to be influenced by this flow. In this study, we explore...
Richie, Helena M. Schneider, Evan E. Abruzzo, Matthew W. Torrey, Paul
Published in
The Astrophysical Journal
We present a suite of high-resolution numerical simulations to study the evolution and survival of dust in hot galactic winds. We implement a novel dust framework in the Cholla hydrodynamics code and use wind tunnel simulations of cool, dusty clouds to understand how thermal sputtering affects the dust content of galactic winds. Our simulations ill...
Das, Subhasish Rauhut, Guntram
Published in
The Astrophysical Journal
Cyclopropenethione falls into the class of complex organic molecules but has not yet been observed in the interstellar medium or any circumstellar disks. However, its existence is very likely, and thus this study provides high-level ab initio predictions, which may serve as reference data for future observations or experimental work. Rovibrational ...
