Search Publications
Windy or Not: Radio Parsec-scale Evidence for a Broad-line Region Wind in Radio-quiet Quasars
Gelfand, Joseph D.; Laor, Ari; Paragi, Zsolt +6 more
Does a broad-line region (BLR) wind in radio-quiet (RQ) active galactic nuclei (AGN) extend to parsec scales and produce radio emission? We explore the correlations between a parsec-scale radio wind and the BLR wind in a sample of 19 RQ Palomar–Green quasars. The radio wind is defined based on the spectral slope and the compactness of the emission…
Shockingly Bright Warm Carbon Monoxide Molecular Features in the Supernova Remnant Cassiopeia A Revealed by JWST
Fransson, C.; Smith, N.; Rest, A. +36 more
We present JWST NIRCam (F356W and F444W filters) and MIRI (F770W) images and NIRSpec Integral Field Unit (IFU) spectroscopy of the young Galactic supernova remnant Cassiopeia A (Cas A) to probe the physical conditions for molecular CO formation and destruction in supernova ejecta. We obtained the data as part of a JWST survey of Cas A. The NIRCam …
A Strongly Lensed Dusty Starburst of an Intrinsic Disk Morphology at a Photometric Redshift of z ph > 7
Yan, Haojing; Cheng, Cheng; Ling, Chenxiaoji +3 more
We present COSBO-7, a strong millimeter source known for more than 16 yr that just revealed its near-to-mid-IR counterpart with the James Webb Space Telescope (JWST). The precise pinpointing by the Atacama Large Millimeter/submillimeter Array on the exquisite NIRCam and MIRI images show that it is a background source gravitationally lensed by a si…
Constraints on Neutron Star Structure from the Clocked X-Ray Burster 1RXS J180408.9-342058
Nagataki, S.; Hashimoto, M.; Dohi, A. +3 more
Type I X-ray bursts are rapid-brightening transient phenomena on the surfaces of accreting neutron stars (NSs). Some X-ray bursts, called clocked bursters, exhibit regular behavior with similar light-curve profiles in their burst sequences. The periodic nature of clocked bursters has the advantage of constraining X-ray binary parameters and physic…
Spectroscopic Observations of the Solar Corona during the 2017 August 21 Total Solar Eclipse: Comparison of Spectral Line Widths and Doppler Shifts between Open and Closed Magnetic Structures
Landi, Enrico; Habbal, Shadia R.; Ding, Adalbert +5 more
The spectroscopic observations presented here were acquired during the 2017 August 21 total solar eclipse (TSE) with a three-channel partially multiplexed imaging spectrometer operating at extremely high orders (>50). The 4 R ⊙ extent of the slit in the north–south direction scanned the corona starting from the central meridian out t…
The Galaxy–Galaxy Strong Lensing Cross Section and the Internal Distribution of Matter in ΛCDM Substructure
Mahler, Guillaume; Meneghetti, Massimo; Jauzac, Mathilde +3 more
Strong gravitational lensing offers a powerful probe of the detailed distribution of matter in lenses, while magnifying and bringing faint background sources into view. Observed strong lensing by massive galaxy clusters, which are often in complex dynamical states, has also been used to map their dark matter (DM) substructures on smaller scales. D…
Realistic Uncertainties for Fundamental Properties of Asteroseismic Red Giants and the Interplay between Mixing Length, Metallicity, and ν max
Li, Yaguang; van Saders, Jennifer; Huber, Daniel +8 more
Asteroseismic modeling is a powerful way to derive stellar properties. However, the derived quantities are limited by built-in assumptions used in stellar models. This work presents a detailed characterization of stellar model uncertainties in asteroseismic red giants, focusing on the mixing-length parameter α MLT, the initial helium fr…
A Multiwavelength Light-curve Model of the Classical Nova V339 Del: A Mechanism for the Coexistence of Dust Dip and Supersoft X-Rays
Kato, Mariko; Hachisu, Izumi; Matsumoto, Katsura
The classical nova V339 Del 2013 is characterized by a 1.5 mag dip of the V light curve owing to a dust shell formation, with which soft X-ray emissions coexist. We present a Strömgren y-band light curve, which represents continuum emission, not influenced by strong [O III] emission lines. The y light curve monotonically decreases in marked contra…
Discovering the Mass-Scaled Damping Timescale from Microquasars to Blazars
Zhang, Haoyang; Yang, Shenbang; Dai, Benzhong
Studying the variability of the accretion disks of black holes and jets is important to identify their internal physical processes. In this Letter, we obtain the characteristic damping timescale of 34 blazars and 7 microquasars from the Fermi-Large Area Telescope and the XMM-Newton X-ray telescope, respectively. We found that the mass-scaled chara…
Updated Proper Motion of the Neutron Star in the Supernova Remnant Cassiopeia A
Holland-Ashford, Tyler; Slane, Patrick; Long, Xi
In this paper, we present updated estimates of the velocity of the neutron star (NS) in the supernova remnant Cassiopeia A using over two decades of Chandra observations. We use two methods: (1) recording the NS positions from dozens of Chandra observations, including the astrometric uncertainty estimates on the data points, but not correcting the…