Search Publications
A Need to Revise Stellar Opacities from Asteroseismology of δ Scuti Stars
Walczak, Przemysław; Daszyńska-Daszkiewicz, Jadwiga; Pamyatnykh, Alexey +2 more
We construct seismic models of the four double-mode radial δ Scuti stars adopting opacities from three databases: OPAL, OP, and OPLIB. The aim is to find the models that fit the observed frequencies of the two radial modes and have the effective temperature and luminosity consistent with the observed values. Using the Bayesian analysis based on Mo…
The Accretion History of AGN: The Spectral Energy Distributions of X-Ray-luminous Active Galactic Nuclei
Kirkpatrick, Allison; Koss, Michael; Boquien, Médéric +17 more
Spectral energy distributions (SEDs) from X-ray to far-infrared (FIR) wavelengths are presented for a sample of 1246 X-ray-luminous active galactic nuclei (AGNs; L 0.5-10 keV > 1043 erg s-1), with z spec < 1.2, selected from Stripe 82X, COSMOS, and GOODS-N/S. The rest-frame SEDs show a wide spread …
Interactions between the Jet and Disk Wind in Nearby Radio-intermediate Quasar III Zw 2
An, Tao; Baan, Willem A.; Mohan, Prashanth +13 more
Disk winds and jets are ubiquitous in active galactic nuclei (AGN), and how these two components interact remains an open question. We study the radio properties of the radio-intermediate quasar III Zw 2. We detect two jet knots, J1 and J2, on parsec scales that move at a mildly apparent superluminal speed of 1.35c. Two γ-ray flares were detected …
Testing the Collisionless Nature of Dark Matter with the Radial Acceleration Relation in Galaxy Clusters
Umetsu, Keiichi; Robertson, Andrew; Tam, Sut-Ieng +1 more
The radial acceleration relation (RAR) represents a tight empirical relation between the inferred total and baryonic centripetal accelerations, g tot = GM tot(< r)/r 2 and g bar = GM bar(< r)/r 2, observed in galaxies and galaxy clusters. The tight correlation between these tw…
JWST Imaging of the Cartwheel Galaxy Reveals Dust Associated with SN 2021afdx
Shivaei, Irene; Sand, David J.; Terreran, Giacomo +12 more
We present near- and mid-infrared (0.9-18 µm) photometry of supernova (SN) 2021afdx, which was imaged serendipitously with the James Webb Space Telescope (JWST) as part of its Early Release Observations of the Cartwheel Galaxy. Our ground-based optical observations show it is likely to be a Type IIb SN, the explosion of a yellow supergiant, …
Electromagnetic Characterization of the LISA Verification Binary ZTF J0526+5934
Bergeron, P.; Kupfer, Thomas; Kosakowski, Alekzander +1 more
We present an analysis of new and archival data to the 20.506 minute LISA verification binary J052610.42+593445.32 (J0526+5934). Our joint spectroscopic and photometric analysis finds that the binary contains an unseen M 1 = 0.89 ± 0.11 M ⊙ CO-core white dwarf primary with an M 2 = 0.38 ± 0.07 M ⊙ post-c…
Lyman Continuum Emission from Spectroscopically Confirmed Lyα Emitters at z 3.1
Jiang, Linhua; Zheng, Zhen-Ya; Windhorst, Rogier A. +2 more
We present a study of Lyman continuum (LyC) emission in a sample of ~150 Lyα emitters (LAEs) at z ≈ 3.1 in the Subaru-XMM Deep Survey field. These LAEs were previously selected using the narrowband technique and spectroscopically confirmed with Lyα equivalent widths (EWs) ≥ 45 Å. We obtain deep UV images using a custom intermediate-band filter U <…
A Three-dimensional Model for the Evolution of Magnetohydrodynamic Turbulence in the Outer Heliosphere
Oughton, Sean; Fichtner, Horst; Kleimann, Jens +1 more
We present a time-dependent, three-dimensional single-fluid model for the transport of magnetohydrodynamic (MHD) turbulence that is self-consistently evolving with a dynamic large-scale solar wind in the outer heliosphere. The emphasis is on the region beyond the termination shock, where the solar wind expands subsonically, as well as sub-Alfvénic…
Shedding New Light on Weak Emission-line Quasars in the C IV-Hβ Parameter Space
Brandt, W. N.; Myers, Adam D.; Strauss, Michael A. +20 more
Weak emission-line quasars (WLQs) are a subset of type 1 quasars that exhibit extremely weak Lyα + N V λ1240 and/or C IV λ1549 emission lines. We investigate the relationship between emission-line properties and accretion rate for a sample of 230 "ordinary" type 1 quasars and 18 WLQs at z < 0.5 and 1.5 < z < 3.5 that have rest-frame ultra…
The Complex X-Ray Obscuration Environment in the Radio-loud Type 2 Quasar 3C 223
Heckman, Timothy; Gandhi, Poshak; Yaqoob, Tahir +4 more
3C 223 is a radio-loud, Type 2 quasar at z = 0.1365 with an intriguing X-ray Multi-mirror Mission (XMM)-Newton spectrum that implicated it as a rare, Compton-thick (N H ≳ 1.25 × 1024 cm-2) active galactic nucleus (AGN). We obtained contemporaneous XMM-Newton and Nuclear Spectroscopic Telescope Array (NuSTAR) spectr…