Search Publications
Assessment of Systematic Uncertainties in the Cosmological Analysis of the SDSS Supernovae Photometric Sample
Scolnic, Dan; Kessler, Richard; Popovic, Brodie
Improvements to the precision of measurements of cosmological parameters with Type Ia supernovae (SNe Ia) are expected to come from large photometrically identified (photometric) supernova (SN) samples. Here we reanalyze the Sloan Digital Sky Survey (SDSS) photometric SN sample, with roughly 700 high-quality, likely but unconfirmed SNe Ia light cu…
Chandra Observations of High-energy X-Ray Sources Discovered by INTEGRAL
Hare, Jeremy; Rahoui, Farid; Fornasini, Francesca M. +6 more
The International Gamma-Ray Astrophysics Laboratory (INTEGRAL) satellite has detected in excess of 1000 sources in the ∼20-100 keV band during its surveys of the sky over the past 17 years. We obtained 5 ks observations of 15 unclassified INTEGRAL Gamma-Ray (IGR) sources with the Chandra X-ray Observatory in order to localize them, to identify opt…
Local Molecular Gas toward the Aquila Rift Region
Chen, Zhiwei; Wang, Hongchi; Gong, Yan +11 more
We present the results of a ∼250 square degrees CO mapping (+26° ≲ l ≲ +50° and -5° ≲ b ≲ +5°) toward the Aquila Rift region at a spatial resolution of ∼50″ and a grid spacing of 30″. The high dynamic range CO maps with a spectral resolution of ∼0.2 km s-1 display highly structured molecular cloud (MC) morphologies with valuable velocit…
The Supernova Remnant Population of NGC 6946 as Observed in [Fe II] 1.644 µm with HST
Blair, William P.; Long, Knox S.; Winkler, P. Frank +1 more
NGC 6946 is a high-star-formation-rate, face-on, spiral galaxy that has hosted 10 supernovae since 1917. Not surprisingly, a large number of supernova remnants and candidates have been identified either as optical nebulae with high [S II]:Hα line ratios (147) or as compact non-thermal radio sources (35). However, there are only seven overlaps betw…
A Year-long Superoutburst from an Ultracompact White Dwarf Binary Reveals the Importance of Donor Star Irradiation
Maccarone, T. J.; Rivera Sandoval, L. E.; Pichardo Marcano, M.
SDSS J080710+485259 is the longest-period outbursting ultracompact white dwarf binary. Its first-ever detected superoutburst started in 2018 November and lasted for a year, the longest detected so far for any short orbital period accreting white dwarf. Here we show the superoutburst duration of SDSS J080710+485259 exceeds the ∼2 month viscous time…
The HSC-SSP Transient Survey: Implications from Early Photometry and Rise Time of Normal Type Ia Supernovae
Tominaga, Nozomu; Nomoto, Ken'ichi; Morokuma, Tomoki +9 more
With a booming number of Type Ia supernovae (SNe Ia) discovered within a few days of their explosions, a fraction of SNe Ia that show luminosity excess in the early phase (early-excess SNe Ia) have been confirmed. In this article, we report early-phase observations of seven photometrically normal SNe Ia (six early detections and one deep non detec…
The Eroding Disk of AU Mic
Augereau, J. -C.; Henning, Th.; Milli, J. +12 more
We report Hubble Space Telescope (HST) Space Telescope Imaging Spectrograph imaging of AU Mic's debris disk from 2017 and archival data. Outward motion of the features in the southeast arm continues. At least three features have reached or exceeded projected escape velocity in the past decade, yielding a combined feature mass-loss rate of ∼1.2 × 1…
Possible Time Correlation between Jet Ejection and Mass Accretion for RW Aur A
Ohyama, Youichi; Pyo, Tae-Soo; Liu, Chun-Fan +17 more
For the active T-Taur star RW Aur A we have performed long-term (∼10 yr) monitoring observations of (1) jet imaging in the [Fe II] 1.644 µm emission line using Gemini-NIFS and VLT-SINFONI; (2) optical high-resolution spectroscopy using CFHT-ESPaDOnS; and (3) V-band photometry using the CrAO 1.25-m telescope and AAVSO. The latter two observat…
On the X-Ray Spectral Energy Distributions of Star-forming Galaxies: The 0.3-30 keV Spectrum of the Low-metallicity Starburst Galaxy VV 114
Hornschemeier, Ann; Basu-Zych, Antara; Garofali, Kristen +6 more
Binary population synthesis combined with cosmological models suggests that X-ray emission from star-forming galaxies, consisting primarily of emission from X-ray binaries (XRBs) and the hot interstellar medium (ISM), could be an important, and perhaps dominant, source of heating of the intergalactic medium prior to the epoch of reionization. Howe…
Relation of Coronal Rain Originating from Coronal Condensations to Interchange Magnetic Reconnection
Peter, Hardi; Li, Leping; Chitta, Lakshmi Pradeep +1 more
Using extreme-ultraviolet images, we recently proposed a new and alternative formation mechanism for coronal rain along magnetically open field lines due to interchange magnetic reconnection. In this paper we report coronal rain at chromospheric and transition region temperatures originating from the coronal condensations facilitated by reconnecti…