Search Publications
The Role of Spiral Arms in Galaxies
Calzetti, Daniela; Battisti, Andrew J.; Sun, Bingqing
We test the influence of spiral arms on the star formation activity of disk galaxies by constructing and fitting multiwavelength spectral energy distributions for the two nearby spiral galaxies NGC 628 and NGC 4321, at a spatial scale of 1–1.5 kpc. Recent results in the literature support the "gatherers" picture, i.e., that spiral arms gather mate…
Four-hundred Very Metal-poor Stars Studied with LAMOST and Subaru. III. Dynamically Tagged Groups and Chemodynamical Properties
Shi, Jianrong; Zhao, Gang; Chen, Yuqin +9 more
Very metal-poor (VMP) stars record the signatures of early accreted galaxies, making them essential tools for unraveling the early stages of Galaxy formation. Understanding the origin of VMP stars requires comprehensive studies of their chemical compositions and kinematics, which are currently lacking. Hence, we conduct a chemodynamical analysis o…
Age of Massive Galaxies at Redshift 8
López-Corredoira, M.; Melia, F.; Wei, J. -J. +1 more
Recent James Webb Space Telescope data analyses have shown that massive red galaxies existed at redshifts z ≳ 6, a discovery that is difficult to understand in the context of standard cosmology (ΛCDM). Here, we analyze these observations more deeply, by fitting a stellar population model to the optical and near-infrared photometric data. These fit…
Deep Chandra Observation of the Remarkable Ionization Cones of NGC 5252
Elvis, Martin; Guainazzi, Matteo; Bianchi, Stefano +4 more
Seyfert galaxy NGC 5252 harbors enormously extended ionization cones that have been previously detected in the optical and X-ray band, offering a unique opportunity to investigate the interaction between the central active galactic nucleus (AGN) and the surrounding gas in the AGN host galaxy. We present deep Chandra imaging spectroscopy of NGC 525…
JWST-FEAST: Feedback in Emerging extrAgalactic Star clusTers: Calibration of Star Formation Rates in the Mid-infrared with NGC 628
Östlin, Göran; Smith, Linda J.; Melinder, Jens +19 more
New JWST near-infrared imaging of the nearby galaxy NGC 628 from the JWST Cycle 1 program Feedback in Emerging extrAgalactic Star clusTers (JWST-FEAST) is combined with archival JWST mid-infrared imaging to calibrate the 21 µm emission as a star formation rate (SFR) indicator at ∼120 pc scales. The Paα (1.8756 µm) hydrogen recombinatio…
X-Ray Characterization of the Pulsar PSR J1849-0001 and Its Wind Nebula G32.64+0.53 Associated with TeV Sources Detected by H.E.S.S., HAWC, Tibet ASγ, and LHAASO
Woo, Jooyun; An, Hongjun; Mori, Kaya +6 more
We report on the X-ray emission properties of the pulsar PSR J1849-0001 and its wind nebula (PWN), as measured by Chandra, XMM-Newton, NICER, Swift, and NuSTAR. In the X-ray data, we detected the 38 ms pulsations of the pulsar up to ~60 keV with high significance. Additionally, we found that the pulsar's on-pulse spectral energy distribution displ…
Quantifying the Transit Light Source Effect: Measurements of Spot Temperature and Coverage on the Photosphere of AU Microscopii with High-resolution Spectroscopy and Multicolor Photometry
Wakeford, Hannah R.; Mann, Andrew W.; Plavchan, Peter +5 more
AU Microscopii (AU Mic) is an active 24 ± 3 Myr pre-main-sequence M dwarf in the stellar neighborhood (d = 9.7 pc) with a rotation period of 4.86 days. The two transiting planets orbiting AU Mic, AU Mic b and c, are warm sub-Neptunes on 8.5 and 18.9 day periods and are targets of interest for atmospheric observations of young planets. Here we stud…
Astroparticles from X-Ray Binary Coronae
Gallagher, John S.; Fang, K.; Halzen, Francis +1 more
The recent observation of high-energy neutrinos from the Galactic plane implies an abundant population of hadronic cosmic-ray sources in the Milky Way. We explore the role of the coronae of accreting stellar-mass black holes as such astroparticle emitters. We show that the particle acceleration and interaction timescales in the coronal region are …
Filament Eruption from Active Region 13283 Leading to a Fast Halo-CME and an Intense Geomagnetic Storm on 2023 April 23
Vemareddy, P.
Using multi-instrument and multiwavelength observations, we studied a coronal mass ejection (CME) that led to an intense geomagnetic storm on 2023 April 23. The eruption occurred on April 21 in solar active region (AR) 13283 near the disk center. The AR was in its decay stage, with fragmented polarities and a preexisting long filament channel a fe…
Insights into the Galactic Bulge Chemodynamical Properties from Gaia Data Release 3
Marinacci, Federico; Fragkoudi, Francesca; Shen, Juntai +4 more
We explore the chemodynamical properties of the Galaxy in the azimuthal velocity V ϕ and metallicity [Fe/H] space using red giant stars from Gaia Data Release 3. The row-normalized V ϕ –[Fe/H] maps form a coherent sequence from the bulge to the outer disk, clearly revealing the thin/thick disk and the Splash. The metal-ric…