Search Publications

Truth or Delusion? A Possible Gravitational Lensing Interpretation of the Ultraluminous Quasar SDSS J010013.02+280225.8 at z = 6.30
DOI: 10.3847/1538-4357/ab718c Bibcode: 2020ApJ...891...64F

Ouchi, Masami; Fujimoto, Seiji; Oguri, Masamune +2 more

Gravitational lensing sometimes dominates the observed properties of apparently very bright objects. We present morphological properties in the high-resolution (FWHM ∼ 0"15) Atacama Large Millimeter/submillimeter Array (ALMA) 1 mm map for an ultraluminous quasar at z = 6.30, SDSS J010013.02+280225.8 (hereafter J0100+2802), whose black hole (BH) ma…

2020 The Astrophysical Journal
Gaia eHST 20
Longitudinal filament oscillations enhanced by two C-class flares
DOI: 10.1051/0004-6361/201937291 Bibcode: 2020A&A...635A.132Z

Guo, J. H.; Zhang, Q. M.; Xu, A. A. +1 more

Context. Large-amplitude, longitudinal filament oscillations triggered by solar flares have been well established in the literature. However, filament oscillations enhanced by flares have never been reported.
Aims: In this paper we report the multiwavelength observations of a very long filament in active region (AR) 11112 on 2010 October 18. …

2020 Astronomy and Astrophysics
SOHO 20
FOXSI-2 Solar Microflares. I. Multi-instrument Differential Emission Measure Analysis and Thermal Energies
DOI: 10.3847/1538-4357/ab7200 Bibcode: 2020ApJ...891...78A

Krucker, Säm; Narukage, Noriyuki; Musset, Sophie +8 more

In this paper we present the differential emission measures (DEMs) of two sub-A class microflares observed in hard X-rays (HXRs) by the FOXSI-2 sounding rocket experiment, on 2014 December 11. The second Focusing Optics X-ray Solar Imager (FOXSI) flight was coordinated with instruments X-ray Telescope (Hinode/XRT) and Solar Dynamics Observatory/At…

2020 The Astrophysical Journal
Hinode 20
Ultra-luminous quasars at redshift z > 4.5 from SkyMapper
DOI: 10.1093/mnras/stz2955 Bibcode: 2020MNRAS.491.1970W

Wolf, Christian; Schmidt, Brian P.; Bian, Fuyan +6 more

The most luminous quasars at high-redshift harbour the fastest growing and most massive black holes in the early Universe. They are exceedingly rare and hard to find. Here, we present our search for the most luminous quasars in the redshift range from z = 4.5 to 5 using data from SkyMapper, Gaia, and WISE. We use colours to select likely high-reds…

2020 Monthly Notices of the Royal Astronomical Society
Gaia 20
Reconnection from a turbulence perspective
DOI: 10.1063/1.5128376 Bibcode: 2020PhPl...27d2305A

Eastwood, J. P.; Matthaeus, W. H.; Stawarz, J. E. +6 more

The spectral properties associated with laminar, anti-parallel reconnection are examined using a 2.5D kinetic particle in cell simulation. Both the reconnection rate and the energy spectrum exhibit three distinct phases: an initiation phase where the reconnection rate grows, a quasi-steady phase, and a declining phase where both the reconnection r…

2020 Physics of Plasmas
Cluster 20
Discovery of molecular gas fueling galaxy growth in a protocluster at z = 1.7
DOI: 10.1051/0004-6361/202038711 Bibcode: 2020A&A...641L...6D

Prandoni, I.; Massardi, M.; Vignali, C. +16 more

Based on ALMA Band 3 observations of the CO(2→1) line transition, we report the discovery of three new gas-rich (MH2 ∼ 1.5 - 4.8 × 1010 M) galaxies in an overdense region at z = 1.7 that already contains eight spectroscopically confirmed members. This leads to a total of 11 confirmed overdensity members…

2020 Astronomy and Astrophysics
eHST 20
Chemical diversity among A-B stars with low rotational velocities: non-LTE abundance analysis
DOI: 10.1093/mnras/staa3099 Bibcode: 2020MNRAS.499.3706M

Ryabchikova, T.; Sitnova, T.; Mashonkina, L. +2 more

We present accurate element abundance patterns based on the non-local thermodynamic equilibrium (non-LTE, NLTE) line formation for 14 chemical elements from He to Nd for a sample of nine A9 to B3-type stars with well-determined atmospheric parameters and low rotational velocities. We constructed new model atom of Zr II-III and updated model atoms …

2020 Monthly Notices of the Royal Astronomical Society
eHST 20
Optical counterpart to Swift J0243.6+6124
DOI: 10.1051/0004-6361/202038333 Bibcode: 2020A&A...640A..35R

Reig, P.; Alfonso-Garzón, J.; Fabregat, J.

Context. Swift J0243.6+6124 is a unique system. It is the first and only ultra-luminous X-ray source in our Galaxy. It is the first and only high-mass Be X-ray pulsar showing radio jet emission. It was discovered during a giant X-ray outburst in October 2017. While there are numerous studies in the X-ray band, very little is known about the optica…

2020 Astronomy and Astrophysics
Gaia 20
The Outburst of the Young Star Gaia19bey
DOI: 10.3847/1538-3881/abad96 Bibcode: 2020AJ....160..164H

Lin, Chien-Cheng; Tonry, John; Magnier, Eugene +10 more

We report photometry and spectroscopy of the outburst of the young stellar object Gaia19bey. We have established the outburst light curve with archival Gaia "G," ATLAS "Orange," Zwicky Transient Facility r-band, and Pan-STARRS "rizy"-filter photometry, showing an outburst of ~4 yr duration, longer than typical EX Lupi objects but shorter than FU O…

2020 The Astronomical Journal
AKARI Gaia 20
Characterizing low-contrast Galactic open clusters with Gaia Data Release 2
DOI: 10.1093/mnras/staa517 Bibcode: 2020MNRAS.493.3473A

Corradi, W. J. B.; Santos, J. F. C.; Angelo, M. S.

In this study, we characterized 16 objects previously classified as faint or low-contrast Galactic open clusters (OCs). We employed parameters associated with the dynamical evolution of the OCs: the core (rc), tidal (rt) and half-mass (rhm) radii, age and crossing time (tcr). Relations among these parame…

2020 Monthly Notices of the Royal Astronomical Society
Gaia 20