Search Publications
Search for traversable wormholes in active galactic nuclei using x-ray data
Tripathi, Ashutosh; Zhou, Biao; Abdikamalov, Askar B. +2 more
In a previous paper, one of us calculated iron K α line profiles emitted from possible accretion disks around traversable wormholes as a first step to use x-ray reflection spectroscopy to search for astrophysical wormholes in active galactic nuclei. In the present paper, we extend that work and construct an XSPEC model for the whole relativistic r…
Galaxy classification: deep learning on the OTELO and COSMOS databases
Bland-Hawthorn, Joss; Gallego, Jesús; Sánchez-Portal, Miguel +19 more
Context. The accurate classification of hundreds of thousands of galaxies observed in modern deep surveys is imperative if we want to understand the universe and its evolution.
Aims: Here, we report the use of machine learning techniques to classify early- and late-type galaxies in the OTELO and COSMOS databases using optical and infrared pho…
Multiscale MHD-Kinetic PIC Study of Energy Fluxes Caused by Reconnection
Lapenta, Giovanni; Berchem, Jean; Walker, Raymond +1 more
We present an analysis of the energy partitioning in the magnetotail during a substorm at 03:58:00 UT on 7 February 2009. The analysis employs a multiscale approach where we use a state from a global magnetohydrodynamics (MHD) model to spawn a kinetic particle-in-cell (PIC) simulation of a large portion of the tail. We directly investigate the ene…
New ultracool dwarf neighbours within 20 pc from Gaia DR2
Scholz, R. -D.
Aims: The Gaia data release 2 (DR2) contains > 6000 objects with parallaxes (Plx + 3 × e_Plx) > 50 mas, placing them within 20 pc from the Sun. Because the expected numbers based on extrapolating the well-known 10 pc census are much lower, nearby Gaia stars need a quality assessment. The 20 pc sample of white dwarfs (WDs) has been verif…
A Tale of Two Transition Disks: ALMA Long-baseline Observations of ISO-Oph 2 Reveal Two Closely Packed Nonaxisymmetric Rings and a ∼2 au Cavity
Flock, Mario; Herczeg, Gregory J.; Pinilla, Paola +12 more
ISO-Oph 2 is a wide-separation (240 au) binary system where the primary star harbors a massive (Mdust ∼ 40 M⊕) ring-like disk with a dust cavity ∼50 au in radius and the secondary hosts a much lighter (Mdust ∼ 0.8 M⊕) disk. As part of the high-resolution follow-up of the "Ophiuchus Disk Survey Employing …
A hyper luminous starburst at z = 4.72 magnified by a lensing galaxy pair at z = 1.48
Daddi, E.; Elbaz, D.; Ilbert, O. +23 more
We serendipitously discovered in the Herschel Reference Survey an extremely bright infrared source with S500 ∼ 120 mJy in the line of sight of the Virgo cluster which we name Red Virgo 4 (RV4). Based on IRAM/EMIR and IRAM/NOEMA detections of the CO(5-4), CO(4-3), and [CI] lines, RV4 is located at a redshift of 4.724, yielding a total ob…
Updated X-ray view of the Hyades cluster
Schmitt, J. H. M. M.; Robrade, J.; Schneider, P. C. +1 more
Aims: We revisit the X-ray properties of the main sequence Hyades members and the relation between X-ray emission and stellar rotation.
Methods: As an input catalog for Hyades members, we combined three recent Hyades membership lists derived from Gaia DR2 data that include the Hyades core and its tidal tails. We searched for X-ray detect…
Molecular Gas Outflow in the Starburst Galaxy NGC 1482
Salak, Dragan; Nakai, Naomasa; Miyamoto, Yusuke +1 more
Galactic winds are essential to the regulation of star formation in galaxies. To study the distribution and dynamics of molecular gas in wind, we imaged the nearby starburst galaxy NGC 1482 in CO (J = 1 → 0) at a resolution of 1″ (≈100 pc) using the Atacama Large Millimeter/submillimeter Array. Molecular gas is detected in a nearly edge-on disk wi…
Characterizing the Circumgalactic Medium of the Lowest-mass Galaxies: A Case Study of IC 1613
Putman, Mary E.; Kirby, Evan N.; Werk, Jessica K. +3 more
Using 10 sight lines observed with the Hubble Space Telescope/Cosmic Origins Spectrograph, we study the circumgalactic medium (CGM) and outflows of IC 1613, which is a low-mass (M* ∼ 108 M⊙), dwarf irregular galaxy on the outskirts of the Local Group. Among the sight lines, four are pointed toward UV-bright stars i…
Confirmation of Enhanced Long-wavelength Dust Emission in OMC 2/3
Friesen, Rachel; Sadavoy, Sarah; Mroczkowski, Tony +8 more
Previous continuum observations from the MUSTANG camera on the Green Bank Telescope (GBT) of the nearby star-forming filament OMC 2/3 found elevated emission at 3.3 mm relative to shorter-wavelength data. As a consequence, the inferred dust emissivity index obtained from modified blackbody dust spectra was considerably lower than what is typically…