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Chandra, NuSTAR, and Optical Observations of the Cataclysmic Variables IGR J17528-2022 and IGR J20063+3641
Mori, Kaya; Thorstensen, John R.; Halpern, Jules P. +5 more
We report on Chandra, NuSTAR, and MDM observations of two International Gamma-ray Astrophysics Laboratory (INTEGRAL) sources, namely IGR J17528-2022 and IGR J20063+3641. IGR J17528-2022 is an unidentified INTEGRAL source, while IGR J20063+3641 was recently identified as a magnetic cataclysmic variable (mCV) by Halpern et al. The Chandra observatio…
A Giant Loop of Ionized Gas Emerging from the Tumultuous Central Region of IC 5063
Ho, Luis C.; Elvis, Martin; Fischer, Travis C. +6 more
The biconical radiation pattern extending from an active galactic nucleus (AGN) may strongly photoionize the circumnuclear interstellar medium (ISM) and stimulate emission from the narrow-line region (NLR). Observations of the NLR may provide clues to the structure of dense material that preferentially obscures the bicone at certain angles, and ma…
FOXSI-2 Solar Microflares. II. Hard X-ray Imaging Spectroscopy and Flare Energetics
Krucker, Säm; Ryan, Daniel F.; Musset, Sophie +7 more
We study the nature of energy release and transfer for two sub-A class solar microflares observed during the second Focusing Optics X-ray Solar Imager (FOXSI-2) sounding rocket flight on 2014 December 11. FOXSI is the first solar-dedicated instrument to utilize focusing optics to image the Sun in the hard X-ray (HXR) regime, sensitive to energies …
Implications of Increased Central Mass Surface Densities for the Quenching of Low-mass Galaxies
Papovich, Casey; Pérez-González, Pablo G.; Bell, Eric F. +12 more
We use the Cosmic Assembly Deep Near-infrared Extragalactic Legacy Survey data to study the relationship between quenching and the stellar mass surface density within the central radius of 1 kpc (Σ1) of low-mass galaxies (stellar mass M* ≲ 109.5 M⊙) at 0.5 ≤ z < 1.5. Our sample is mass complete down t…
The Characterization of the Dust Content in the Ring Around Sz 91: Indications of Planetesimal Formation?
Palau, Aina; Carrasco-González, Carlos; Olofsson, Johan +6 more
One of the most important questions in the field of planet formation is how millimeter- and centimeter-sized dust particles overcome radial drift and fragmentation barriers to form kilometer-sized planetesimals. ALMA observations of protoplanetary disks, in particular transition disks or disks with clear signs of substructures, can provide new con…
A Preliminary Calibration of the JAGB Method Using Gaia EDR3
Madore, Barry F.; Freedman, Wendy L.; Lee, Abigail J. +2 more
The recently developed J-region asymptotic giant branch (JAGB) method has extraordinary potential as an extragalactic standard candle, capable of calibrating the absolute magnitudes of locally accessible Type Ia supernovae, thereby leading to an independent determination of the Hubble constant. Using Gaia Early Data Release 3 (EDR3) parallaxes, we…
Gas Infalling Motions in the Envelopes of Very Low Luminosity Objects
Kim, Gwanjeong; Kim, Mi-Ryang; Lee, Chang Won +2 more
We present the results of a single-dish survey toward 95 very low luminosity objects (VeLLOs) in optically thick (HCN 1-0) and thin (N2H+ 1-0) lines performed for the purpose of understanding the physical processes of inward motions in the envelopes of the VeLLOs and characterizing their true nature. The normalized velocity d…
The Stellar Initial Mass Function and Population Properties of M89 from Optical and NIR Spectroscopy: Addressing Biases in Spectral Index Analysis
Freedman, Wendy L.; Feldmeier-Krause, A.; Lonoce, I.
The complexity of constraining the stellar initial mass function (IMF) in early-type galaxies cannot be overstated, given the necessity of very high signal-to-noise ratio (S/N) data and the difficulty of breaking the strong degeneracies that occur among several stellar population parameters, including age, metallicity, and elemental abundances. Wi…
NOEMA Redshift Measurements of Extremely Bright Submillimeter Galaxies near the GOODS-N
Cowie, Lennox L.; Barger, Amy J.; Jones, Logan H. +1 more
We report spectroscopic redshift measurements for three bright submillimeter galaxies (SMGs) near the GOODS-N field, each with SCUBA-2 850 µm fluxes >10 mJy, using the Northern Extended Millimeter Array (NOEMA). Our molecular line-scan observations of these sources, which occupy an ~7 arcmin2 area outside of the Hubble Space Te…
On the Possibility of Stellar Lenses in the Black Hole Candidate Microlensing Events MACHO-96-BLG-5 and MACHO-98-BLG-6
Lu, Jessica R.; Abdurrahman, Fatima N.; Stephens, Haynes F.
Although stellar-mass black holes (BHs) are likely to be abundant in the Milky Way (N = 108-109), only 20 have been detected to date, all in accreting binary systems. Gravitational microlensing is a proposed technique to search for isolated BHs, which have not yet been detected. Two specific microlensing events, MACHO-1996-BL…