Search Publications
Spectral break of energetic pulsar wind nebulae detected with wideband X-ray observations
Terada, Yukikatsu; Uchida, Hiroyuki; Bamba, Aya +4 more
Pulsar wind nebulae (PWNe) are one of the most energetic galactic sources with bright emissions from radio waves to very high-energy gamma-rays. We perform wideband X-ray spectroscopy of four energetic PWNe, N 157 B, PSR J1813-1749, PSR J1400-6325, and G21.5-0.9, with the Suzaku, Chandra, NuSTAR, and Hitomi observatories. A significant spectral br…
Jupiter's X-Ray and UV Dark Polar Region
Jackman, C. M.; Johnson, R. E.; Branduardi-Raymont, G. +16 more
We present 14 simultaneous Chandra X-ray Observatory (CXO)-Hubble Space Telescope (HST) observations of Jupiter's Northern X-ray and ultraviolet (UV) aurorae from 2016 to 2019. Despite the variety of dynamic UV and X-ray auroral structures, one region is conspicuous by its persistent absence of emission: the dark polar region (DPR). Previous HST o…
Galactic H II region IRAS 17149 - 3916 - a multiwavelength study
Tej, Anandmayee; Das, Swagat R.; Vig, Sarita +3 more
This paper presents a multiwavelength investigation of the Galactic H II region IRAS 17149 - 3916. Using the Giant Meterwave Radio Telescope, India, first low-frequency radio continuum observations at 610 and 1280 MHz for this region are presented. The ionized gas emission displays an interesting cometary morphology, which is likely powered by the…
AstroSat View of Spectral Transition in the Changing-look Active Galaxy NGC 1566 during the Declining Phase of the 2018 Outburst
Dewangan, Gulab C.; Tripathi, Prakash
NGC 1566 is a changing-look active galaxy that exhibited an outburst during 2017-2018 with a peak in 2018 June. We triggered AstroSat observations of NGC 1566 twice in 2018 August and October during its declining phase. Using the AstroSat observations, along with two XMM-Newton observations in 2015 (pre-outburst) and 2018 June (peak outburst), we …
A spectroscopic quadruple as a possible progenitor of sub-Chandrasekhar type Ia supernovae
Zwitter, Tomaž; Traven, Gregor; Gilmore, Gerry +13 more
Binaries have received much attention as possible progenitors of type Ia supernova explosions1, but long-term gravitational effects2,3 in tight triple or quadruple systems could also play a key role in producing type Ia supernovae. Here we report on the properties of a spectroscopic quadruple found within a star cluster: the …
CHANG-ES. XXIV. First Detection of a Radio Nuclear Ring and Potential LLAGN in NGC 5792
Wang, Q. Daniel; Li, Zhiyuan; Sun, Wei +8 more
We report the discoveries of a nuclear ring of diameter 10″ (~1.5 kpc) and a potential low-luminosity active galactic nucleus (LLAGN) in the radio continuum emission map of the edge-on barred spiral galaxy NGC 5792. These discoveries are based on the Continuum Halos in Nearby Galaxies-an Expanded Very Large Array (VLA) Survey, as well as subsequen…
A Selection of Hα Emitters at z = 2.1-2.5 Using the K s -band Photometry of ZFOURGE
Spitler, Lee R.; Motohara, Kentaro; Chen, Nuo +1 more
Large and less-biased samples of star-forming galaxies are essential to investigate galaxy evolution. Hα emission line is one of the most reliable tracers of star-forming galaxies because its strength is directly related to recent star formation. However, it is observationally expensive to construct large samples of Hα emitters by spectroscopic or…
Discordance analysis on a high-resolution valley network map of Mars: Assessing the effects of scale on the conformity of valley orientation and surface slope direction
Bahia, Rickbir S.; Covey-Crump, Stephen; Jones, Merren A. +1 more
Fluvial valleys incised into planetary surfaces display morphologies, geometries and orientations that can be used to understand their controlling processes. Comparisons between valley orientations and topographic surface slope direction have been used to understand how Martian surfaces have evolved (Luo and Stepinski, 2012; Black et al., 2017); h…
Very Large Telescope MUSE Observations of the Bubble Nebula around NGC 1313 X-2 and Evidence for Additional Photoionization
Feng, Hua; Bian, Fuyan; Zhou, Changxing +1 more
The bubble nebula surrounding NGC 1313 X-2 is believed to be powered by high velocity winds from the central ultraluminous X-ray source (ULX) as a result of supercritical accretion. With the Multi-Unit Spectroscopic Explorer (MUSE) observation of the nebula, we find enhanced [O III] emission at locations spatially coincident with clusters of stars…
The high energy spectrum of Proxima Centauri simultaneously observed at X-ray and FUV wavelengths
Czesla, S.; France, K.; Predehl, P. +6 more
The M dwarf Proxima Centauri, the Sun's closest stellar neighbour, is known to be magnetically active and it hosts a likely Earth-like planet in its habitable zone. High-energy radiation from the host star can significantly alter planetary atmospheres in close orbits. Frequent flaring may drive radiation-induced effects such as rapid atmospheric e…