Search Publications
Migration jumps of planets in transition discs
Rometsch, Thomas; Rodenkirch, Peter J.; Kley, Wilhelm +1 more
Context. Transition discs form a special class of protoplanetary discs that are characterised by a deficiency of disc material close to the star. In a subgroup, inner holes in these discs can stretch out to a few tens of au while there is still mass accretion onto the central star observed at the same time.
Aims: We analyse the proposition th…
A Comprehensive Study of Hα Emitters at z ∼ 0.62 in the DAWN Survey: The Need for Deep and Wide Regions
Finkelstein, Steven L.; Mobasher, Bahram; Zheng, Zhen-Ya +19 more
We present new estimates of the luminosity function (LF) and star formation rate density (SFRD) for an Hα-selected sample at z ∼ 0.62 from the Deep And Wide Narrow-band (DAWN) survey. Our results are based on a new Hα sample in the extended COSMOS region (compared to Coughlin et al.) with the inclusion of flanking fields, resulting in a total area…
Evolution of MAXI J1631-479 during the January 2019 outburst observed by INTEGRAL/IBIS
Masetti, N.; Charles, P. A.; Bird, A. J. +8 more
We report on a recent bright outburst from the new X-ray binary transient MAXI J1631-479, observed in January 2019. In particular, we present the 30-200 keV analysis of spectral transitions observed with INTEGRAL/IBIS during its Galactic plane monitoring program. In the MAXI and BAT monitoring period, we observed two different spectral transitions…
Imagery and UV Spectroscopy of the LMC Supernova Remnant N103B Using HST
Blair, William P.; Raymond, John C.; Pirzkal, Norbert +6 more
We present Hubble Space Telescope (HST)/Wide Field Camera 3 multiband imagery of N103B, which is the remnant of a SN Ia in the Large Magellanic Cloud, as well as HST/Cosmic Origins Spectrograph (COS) ultraviolet spectroscopy of the brightest radiatively shocked region. The images show a wide range of morphology and relative emission-line intensiti…
Predicting frequency changes of global-scale solar Rossby modes due to solar cycle changes in internal rotation
Birch, A. C.; Gizon, L.; Fournier, D. +1 more
Context. Large-scale equatorial Rossby modes have been observed on the Sun over the last two solar cycles.
Aims: We investigate the impact of the time-varying zonal flows on the frequencies of Rossby modes.
Methods: A first-order perturbation theory approach is used to obtain an expression for the expected shift in the mode frequencies d…
Characteristics of Reconnection Sites and Fast Flow Channels in an MHD Simulation
McPherron, R. L.; El-Alaoui, M.; Walker, R. J. +1 more
We investigate an interval of moderate magnetic activity from 0-8 UT on 14 March 2008 by using a global magnetohydrodynamics (MHD) simulation with high spatial and temporal resolution. Observations show several distinct substorms during this interval. One of these with onset at 04:44 UT occurs at 04:42 UT in the simulation. The simulation shows re…
Probing multicomponent FIMP scenarios with gamma-ray telescopes
Ibarra, Alejandro; Herms, Johannes
We consider a scenario where the dark sector includes two Feebly Interacting Massive Particles (FIMPs), with couplings to the Standard Model particles that allow their production in the Early Universe via thermal freeze-in. These couplings generically lead to the decay of the heavier dark matter component into the lighter, possibly leading to obse…
Interplanetary consequences and geoeffectiveness of CME associated with major solar flare from NOAA AR 12673
Soni, Shirsh Lata; Gupta, Radhe Shyam; Verma, Pyare Lala
In this reported work, we study a major X-class flare (X9.3) that arose from NOAA Active Region (AR) 12673 on 2017 September 6, from 11:53 UT to 12:10 UT in multi-wavelength views. This event also produced a fast coronal mass ejection (CME). NOAA AR 12673 emerged at S09W30 on 2017 September 6 and grew rapidly to a large AR. On 2017 September 9, th…
The Ophiuchus stream progenitor: a new type of globular cluster and its possible Sagittarius connection
Bovy, Jo; Fattahi, Azadeh; Navarro, Julio F. +2 more
The Ophiuchus stream is a short arc-like stellar feature of uncertain origin located ∼5 kpc North of the Galactic centre. New proper motions from the second Gaia data release reconcile the direction of motion of stream members with the stream arc, resolving a puzzling mismatch reported in earlier work. We use N-body simulations to show that the st…
Unexpected late-time temperature increase observed in the two neutron star crust-cooling sources XTE J1701-462 and EXO 0748-676
Degenaar, N.; Wijnands, R.; Homan, J. +4 more
Transient low-mass X-ray binaries (LMXBs) that host neutron stars (NSs) provide excellent laboratories for probing the dense matter physics present in NS crusts. During accretion outbursts in LMXBs, exothermic reactions may heat the NS crust, disrupting the crust-core equilibrium. When the outburst ceases, the crust cools to restore thermal equili…