Search Publications

Study of the Decay Rates of the Umbral Area of Sunspot Groups Using a High-resolution Database
DOI: 10.3847/1538-4357/ab7898 Bibcode: 2020ApJ...892..107M

Muraközy, Judit

The emergence and decay of the sunspot groups are important components of the solar dynamo models. There are two different types of studies on the evolution of active regions. One of them is based on fewer data with higher spatial resolution, the other one uses more data with lower spatial resolution. The input data of the present study allow the …

2020 The Astrophysical Journal
SOHO 12
The Space Environment and Atmospheric Joule Heating of the Habitable Zone Exoplanet TOI 700 d
DOI: 10.3847/1538-4357/ab9637 Bibcode: 2020ApJ...897..101C

Drake, Jeremy J.; Garraffo, C.; Alvarado-Gómez, J. D. +4 more

We investigate the space environment conditions near the Earth-size planet TOI 700 d using a set of numerical models for the stellar corona and wind, the planetary magnetosphere, and the planetary ionosphere. We drive our simulations using a scaled-down stellar input and a scaled-up solar input in order to obtain two independent solutions. We find…

2020 The Astrophysical Journal
Ulysses 12
New constraints on the HR 8799 planetary system from mid-infrared direct imaging
DOI: 10.1093/mnras/stz3117 Bibcode: 2020MNRAS.491.1795P

Fedele, D.; Kissler-Patig, M.; van den Ancker, M. E. +2 more

Direct imaging is a tried and tested method of detecting exoplanets in the near-infrared (IR), but has so far not been extended to longer wavelengths. New data at mid-IR wavelengths (8-20 µm) can provide additional constraints on planetary atmospheric models. We use the VLT Imager and Spectrometer for the mid-IR (VISIR) instrument on the VLT…

2020 Monthly Notices of the Royal Astronomical Society
Gaia 12
OGLE-2018-BLG-1269Lb: A Jovian Planet with a Bright I = 16 Host
DOI: 10.3847/1538-3881/abacc8 Bibcode: 2020AJ....160..148J

Han, Cheongho; Udalski, Andrzej; Lee, Chung-Uk +57 more

We report the discovery of a planet in the microlensing event OGLE-2018-BLG-1269 with a planet-host mass ratio q ∼ 6 × 10-4, i.e., 0.6 times smaller than the Jupiter/Sun mass ratio. Combined with the Gaia parallax and proper motion, a strong one-dimensional constraint on the microlens parallax vector allows us to significantly reduce th…

2020 The Astronomical Journal
Gaia 12
A detailed study on the reflection component for the black hole candidate MAXI J1836-194
DOI: 10.1093/mnras/staa401 Bibcode: 2020MNRAS.493.2178D

Gou, Lijun; García, Javier A.; Liu, Zhu +3 more

We present a detailed spectral analysis of the black hole candidate MAXI J1836-194. The source was caught in the intermediate state during its 2011 outburst by Suzaku and RXTE. We jointly fit the X-ray data from these two missions using the relxill model to study the reflection component, and a steep inner emissivity profile indicating a compact c…

2020 Monthly Notices of the Royal Astronomical Society
Suzaku 12
Extending the view of ArH+ chemistry in diffuse clouds
DOI: 10.1051/0004-6361/202039197 Bibcode: 2020A&A...643A..91J

Wyrowski, Friedrich; Menten, Karl M.; Jacob, Arshia M. +2 more

Context. One of the surprises of the Herschel mission was the detection of ArH+ towards the Crab Nebula in emission and in absorption towards strong Galactic background sources. Although these detections were limited to the first quadrant of the Galaxy, the existing data suggest that ArH+ ubiquitously and exclusively probes t…

2020 Astronomy and Astrophysics
Herschel 12
Infrared Properties of Asymptotic Giant Branch Stars in Our Galaxy and the Magellanic Clouds
DOI: 10.3847/1538-4357/ab6609 Bibcode: 2020ApJ...891...43S

Suh, Kyung-Won

We investigate the infrared properties of asymptotic giant branch (AGB) stars in our Galaxy and the Magellanic Clouds using various infrared observational data and theoretical models. We use catalogs for the sample of 4996 AGB stars in our Galaxy and about 39,000 AGB stars in the Magellanic Clouds from the available literature. For each object in …

2020 The Astrophysical Journal
AKARI 12
A Larger Extent for the Ophiuchus Stream
DOI: 10.3847/1538-3881/ab8cbf Bibcode: 2020AJ....159..287C

Caldwell, Nelson; Price-Whelan, Adrian M.; Bonaca, Ana +2 more

We present new kinematic data for the Ophiuchus stellar stream. Spectra have been taken of member candidates at the MMT telescope using Hectospec, Hectochelle, and Binospec, which provide more than 1800 new velocities. Combined with proper-motion measurements of stars in the field by the Gaia—DR2 catalog, we have derived stream membership probabil…

2020 The Astronomical Journal
Gaia 12
Host galaxy properties and environment of obscured and unobscured X-ray selected active galactic nuclei in the COSMOS survey
DOI: 10.1093/mnras/staa723 Bibcode: 2020MNRAS.494.1189B

Bornancini, C.; García Lambas, D.

We analyse different photometric and spectroscopic properties of active galactic nuclei (AGNs) and quasars (QSOs) selected by their mid-IR power-law and X-ray emission from the COSMOS survey. We use a set of star-forming galaxies as a control sample to compare with the results. We have considered samples of obscured (HR > -0.2) and unobscured (…

2020 Monthly Notices of the Royal Astronomical Society
eHST 12
Cosmological 3D H I Gas Map with HETDEX Lyα Emitters and eBOSS QSOs at z = 2: IGM-Galaxy/QSO Connection and a ∼40 Mpc Scale Giant H II Bubble Candidate
DOI: 10.3847/1538-4357/abb81b Bibcode: 2020ApJ...903...24M

Ono, Yoshiaki; Ouchi, Masami; Finkelstein, Steven L. +20 more

We present cosmological (30-400 Mpc) distributions of neutral hydrogen (H I) in the intergalactic medium (IGM) traced by Lyα emitters (LAEs) and QSOs at z = 2.1-2.5, selected with the data of the ongoing Hobby-Eberly Telescope Dark Energy Experiment (HETDEX) and the eBOSS survey. Motivated by a previous study of Mukae et al., we investigate spatia…

2020 The Astrophysical Journal
eHST 12