Search Publications
Analysis of a Century’s Worth of AR Scorpii Photometry from DASCH and ASAS-SN
Garnavich, Peter; Littlefield, Colin; Peterson, Erik
AR Scorpii (AR Sco) is a binary star system containing the only known white dwarf (WD) pulsar. Previously reported photometric data sets only provide coverage back to 2005, but we extend the observational baseline for AR Sco back to the beginning of the 20th century by analyzing observations from the Digital Access to a Sky Century at Harvard proj…
Gas Accretion within the Dust Cavity in AB Aur
Rivière-Marichalar, Pablo; Fuente, Asunción; Baruteau, Clément +5 more
AB Aur is a Herbig Ae star hosting a well-known transitional disk. Because of its proximity and low inclination angle, it is an excellent object to study planet formation. Our goal is to investigate the chemistry and dynamics of the molecular gas component in the AB Aur disk, and its relation with the prominent horseshoe shape observed in continuu…
A deeper look at the dust attenuation law of star-forming galaxies at high redshift
Bressan, A.; Pérez-González, P. G.; Barro, G. +4 more
A diverse range of dust attenuation laws is found in star-forming galaxies. In particular, Tress et al. (2018) studied the SHARDS survey to constrain the NUV bump strength (B) and the total-to-selective ratio (RV) of 1753 star-forming galaxies in the GOODS-N field at 1.5 < z < 3. We revisit here this sample to assess the implicati…
Polarisation of a small-scale cometary plasma environment. Particle-in-cell modelling of comet 67P/Churyumov-Gerasimenko
Nilsson, Hans; Goetz, Charlotte; Gunell, Herbert +2 more
Context. The plasma near the nucleus of a comet is subjected to an electric field to which a few different sources contribute: the convective electric field of the solar wind, the ambipolar electric field due to higher electron than ion speeds, and a polarisation field arising from the vastly different ion and electron trajectories.
Aims: Our…
Properties of the transient X-ray pulsar Swift J1816.7-1613 and its optical companion
Tsygankov, Sergey S.; Lutovinov, Alexander A.; Poutanen, Juri +4 more
We present results of investigation of the poorly studied X-ray pulsar
Discovery of a radio transient in M81
Gandhi, P.; Miller-Jones, J. C. A.; Fender, R. P. +9 more
We report the discovery of a radio transient in the spiral galaxy M81. The transient was detected in early 2015 as part of a two-year survey of M81 made up of 12 epochs using the Karl G. Jansky Very Large Array. While undetected on 2014 September 12, the source was first detected on 2015 January 2, from which point it remained visible at an approx…
Multiband Study of a Bidirectional Jet Occurred in the Upper Chromosphere
Reeves, Katharine K.; Ni, Lei; Lin, Jun +3 more
We present a study of a jet observed by the Solar Dynamics Observatory (SDO) and the Interface Region Imaging Spectrograph (IRIS), which provide high spatial-temporal resolution observational data of (extreme) ultraviolet images, spectra, and magnetograms. The jet was observed in multiple bands of AIA and manifested clear bidirectional flows in IR…
Direct detection anomalies in light of G A I A data
Buckley, Matthew R.; Mohlabeng, Gopolang; Murphy, Christopher W.
Measurements from the GAIA satellite have greatly increased our knowledge of the dark matter velocity distributions in the Solar neighborhood. There is evidence for multiple cold structures nearby, including a high-velocity stream counterrotating relative to the Sun. This stream could significantly alter the spectrum of recoil energies and increas…
The beamed jet and quasar core of the distant blazar 4C 71.07
Lähteenmäki, A.; Giroletti, M.; Villata, M. +61 more
The object 4C 71.07 is a high-redshift blazar whose spectral energy distribution shows a prominent big blue bump and a strong Compton dominance. We present the results of a 2-yr multiwavelength campaign led by the Whole Earth Blazar Telescope (WEBT) to study both the quasar core and the beamed jet of this source. The WEBT data are complemented by …
Quiescent X-ray variability in the neutron star Be/X-ray transient GRO J1750-27
Degenaar, N.; Wijnands, R.; Kaper, L. +5 more
The Be/X-ray transient GRO J1750-27 exhibited a type-II (giant) outburst in 2015. After the source transited to quiescence, we triggered our multi-year Chandra monitoring programme to study its quiescent behaviour. The programme was designed to follow the cooling of a potentially heated neutron-star crust due to accretion of matter during the prec…