Search Publications
Possible detection of a new cyclotron feature in 4U 1700-37
Roy, Jayashree; Bhattacharya, Dipankar; Bala, Suman
We present a spectral and timing study of the high-mass X-ray binary transient source 4U 1700-37 using NuSTAR and ASTROSAT/LAXPC. The source is observed in two different flux states. A combined spectral analysis of NuSTAR's focal plane modules A and B shows the possible hint of a cyclotron line feature at ∼16 keV. The line feature is consistently …
Recovering variable stars in large surveys: EAup Algol-type class in the Catalina Survey
Drake, A. J.; Papageorgiou, A.; Catelan, M. +5 more
The discovery and characterization of Algol eclipsing binaries (EAs) provide an opportunity to contribute for a better picture of the structure and evolution of low-mass stars. However, the cadence of most current photometric surveys hinders the detection of EAs since the separation between observations is usually larger than the eclipse(s) durati…
Discovery of radio jets in the Phoenix galaxy cluster center
Kohno, Kotaro; Oguri, Masamune; Kawabe, Ryohei +6 more
We report the results of the Australia Telescope Compact Array (ATCA) 15 mm observation of the Phoenix galaxy cluster possessing an extreme star-burst brightest cluster galaxy (BCG) at the cluster center. We spatially resolved radio emission around the BCG, and found diffuse bipolar and bar-shape structures extending from the active galactic nucle…
A New Metal-poor Globular Cluster and Resolved Stars in the Outer Disk of the Black Eye Galaxy M64: Implication for the Origin of the Type III Disk Break
Lee, Myung Gyoon; Kang, Jisu; Jang, In Sung +1 more
M64 is a nearby spiral galaxy with a Type III antitruncation component. To trace the origin of the Type III component, we present Hubble Space Telescope/Advanced Camera for Surveys (ACS) F606W/F814W photometry of resolved stars in a field located in the outer disk ( $2\buildrel{\,\prime}\over{.} 5\lesssim r\lesssim 6\buildrel{\,\prime}\over{.} 5$ …
Spectrophotometric characterization of the Philae landing site and surroundings with the Rosetta/OSIRIS cameras
Sierks, H.; Güttler, C.; Barucci, M. A. +5 more
We investigate Abydos, the final landing site of the Philae lander after its eventful landing from the Rosetta spacecraft on comet 67P/Churyumov-Gerasimenko on 2014 November 12. Over 1000 OSIRIS-level 3B images were analysed, which cover the 2014 August-2016 September timeframe, with spatial resolution ranging from 7.6 m pixel-1 to appr…
First Results from a Panchromatic HST/WFC3 Imaging Study of the Young, Rapidly Evolving Planetary Nebulae NGC 7027 and NGC 6302
Frank, Adam; Balick, Bruce; Kastner, Joel H. +3 more
We present the first results from comprehensive, near-UV-to-near-IR Hubble Space Telescope Wide Field Camera 3 (WFC3) emission-line imaging studies of two young planetary nebulae (PNe), NGC 7027 and NGC 6302. These two objects represent key sources for purposes of understanding PNe shaping processes. Both nebulae feature axisymmetric and point-sym…
NuSTAR Observations of G11.2-0.3
Fryer, C. L.; Grefenstette, B. W.; Madsen, K. K. +3 more
We present in this paper the hard X-ray view of the pulsar wind nebula in G11.2-0.3 and its central pulsar powered pulsar J1811-1925 as seen by NuSTAR. We complement the data with Chandra for a more complete picture and confirm the existence of a hard, power-law component in the shell with photon index ${\rm{\Gamma }}=2.1\pm 0.1$ , which we attrib…
Two Successive Type II Radio Bursts Associated with B-class Flares and Slow CMEs
Chen, Huadong; Ma, Suli
3 From 2018 Oct 12 to 13, three successive solar eruptions (E1-E3) with B-class flares and poor 4 white light coronal mass ejections (CMEs) occurred from the same active region NOAA AR 12724. 5 Interestingly, the first two eruptions are associated with Type II radio bursts but the third is not. 6 Using the soft X-ray flux data, radio dynamic spect…
Search for Zeeman-splitting of OH 6.035 GHz line in the young planetary nebula K 3-35
Hou, L. G.; Gao, X. Y.
Magnetic field could play a role in the formation and early evolution of non-spherical planetary nebulae (PNe). The predominant source of information of the magnetic fields in PNe is the polarization observations of maser emission. To date, distinct and/or possible Zeeman pairs have only been reported towards four PNe by measuring the OH ground-st…
Continuum Enhancements, Line Profiles, and Magnetic Field Evolution during Consecutive Flares
Mathioudakis, Mihalis; Murabito, Mariarita; Guglielmino, Salvo L. +5 more
During solar flares, magnetic energy can be converted into electromagnetic radiation from radio waves to γ-rays. Enhancements in the continuum at visible wavelengths, as well as continuum enhancements in the FUV and NUV passbands, give rise to white-light flares. In addition, the strong energy release in these events can lead to the rearrangement …