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Cosmic-rays, gas, and dust in nearby anticentre clouds. II. Interstellar phase transitions and the dark neutral medium
Marshall, D. J.; Casandjian, J. M.; Grenier, I. A. +1 more
Aim. H I 21-cm and 12CO 2.6-mm line emissions trace the atomic and molecular gas phases, respectively, but they miss most of the opaque H I and diffuse H2 present in the dark neutral medium (DNM) at the transition between the H I-bright and CO-bright regions. Jointly probing H I, CO, and DNM gas, we aim to constrain the thres…
The reduction of magnetic reconnection outflow jets to sub-Alfvénic speeds
Haggerty, Colby C.; Shay, Michael A.; Chasapis, Alexandros +5 more
The outflow velocity of jets produced by collisionless magnetic reconnection is shown to be reduced by the ion exhaust temperature in fully kinetic particle in cell simulations and in situ satellite observations. We derive a scaling relationship for the outflow velocity based on the upstream Alfvén speed and the parallel ion exhaust temperature, w…
Follow-up Imaging of Disk Candidates from the Disk Detective Citizen Science Project: New Discoveries and False Positives in WISE Circumstellar Disk Surveys
Baranec, Christoph; Riddle, Reed; Debes, John H. +17 more
The Disk Detective citizen science project aims to find new stars with excess 22 µm emission from circumstellar dust in the AllWISE data release from the Wide-field Infrared Survey Explorer. We evaluated 261 Disk Detective objects of interest with imaging with the Robo-AO adaptive optics instrument on the 1.5 m telescope at Palomar Observato…
K2-232 b: a transiting warm Saturn on an eccentric P = 11.2 d orbit around a V = 9.9 star
Jones, M. I.; Rabus, M.; Espinoza, N. +12 more
We report the discovery of K2-232 b using photometric data of the Kepler K2 satellite coupled with ground-based spectroscopic observations. K2-232 b has a mass of MP = 0.397 ± 0.037 MJ, a radius of RP = 1.00 ± 0.020 RJ, and a moderately low equilibrium temperature of Teq = 1030 ± 15 K due to i…
A multiwavelength study of SXP 1062, the long-period X-ray pulsar associated with a supernova remnant
Haberl, F.; Gallagher, J.; Guerrero, M. A. +5 more
SXP 1062 is a Be X-ray binary (BeXB) located in the Small Magellanic Cloud. It hosts a long-period X-ray pulsar and is likely associated with the supernova remnant MCSNR J0127-7332. In this work we present a multiwavelength view on SXP 1062 in different luminosity regimes. We consider monitoring campaigns in optical (OGLE survey) and X-ray (Swift …
Galaxy pre-processing in substructures around z ∼ 0.4 galaxy clusters
Demarco, R.; Balestra, I.; Rosati, P. +5 more
We present a detailed analysis of galaxy colours in two galaxy clusters at z ∼ 0.4, MACS J0416.1 - 2403 and MACS J1206.2 - 0847, drawn from the CLASH-VLT survey, to investigate the role of pre-processing in the quenching of star formation. We estimate the fractions of red and blue galaxies within the main cluster and the detected substructures and…
Characterization of Stellar and Substellar Members in the Coma Berenices Star Cluster
Herczeg, Gregory J.; Jose, Jessy; Tang, Shih-Yun +3 more
We have identified stellar and substellar members in the nearby star cluster Coma Berenices, using photometry, proper motions, and distances of a combination of 2MASS, UKIDSS, URAT1, and Gaia/DR2 data. Those with Gaia/DR2 parallax measurements provide the most reliable sample to constrain the distance, averaging 86.7 pc with a dispersion of 7.1 pc…
Globular clusters in high-redshift dwarf galaxies: a case study from the Local Group
Weisz, Daniel R.; Zick, Tom O.; Boylan-Kolchin, Michael
We present the reconstructed evolution of rest-frame ultraviolet (UV) luminosities of the most massive Milky Way dwarf spheroidal satellite galaxy, Fornax, and its five globular clusters (GCs) across redshift, based on analysis of the stellar fossil record and stellar population synthesis modelling. We find that (1) Fornax's (proto-)GCs can genera…
The Fermi-LAT detection of magnetar-like pulsar PSR J1846-0258 at high-energy gamma-rays
Dekker, A.; Kuiper, L.; Hermsen, W.
We report the detection of the pulsed signal of the radio-quiet magnetar-like pulsar PSR J1846-0258 in the high-energy γ-ray data of the Fermi Large Area Telescope (Fermi LAT). We produced phase-coherent timing models exploiting RXTE PCA and Swift XRT monitoring data for the post- (magnetar-like) outburst period from 2007 August 28 to 2016 Septemb…
Spectroscopic and imaging observations of small-scale reconnection events
Li, Dong; Li, Leping; Ning, Zongjun
We present spectroscopic and imaging observations of small-scale reconnection events on the Sun. Using Interface Region Imaging Spectrograph (IRIS) observations, one reconnection event is first detected as IRIS jets with fast bidirectional velocities in the chromosphere and transition region, which are identified as non-Gaussian broadenings with t…