Search Publications
ATCA observations of the MACS-Planck Radio Halo Cluster Project. I. New detection of a radio halo in PLCK G285.0-23.7
Brunetti, G.; Aghanim, N.; Douspis, M. +12 more
Aims: We investigate the possible presence of diffuse radio emission in the intermediate redshift, massive cluster PLCK G285.0-23.7 (z = 0.39, M500 = 8.39 × 1014M⊙).
Methods: Our 16 cm-band ATCA observations of PLCK G285.0-23.7 allow us to reach a rms noise level of 11 µJy/beam on the wide-band (1.1…
Deep ALMA imaging of the merger NGC 1614. Is CO tracing a massive inflow of non-starforming gas?
Gallagher, J. S.; Xu, C. K.; Evans, A. +4 more
Aims: Observations of the molecular gas over scales of ~0.5 to several kpc provide crucial information on how molecular gas moves through galaxies, especially in mergers and interacting systems, where it ultimately reaches the galaxy center, accumulates, and feeds nuclear activity. Studying the processes involved in the gas transport is one o…
Compact Galactic Planetary Nebulae: An HST/WFC3 Morphological Catalog, and a Study of Their Role in the Galaxy
Villaver, Eva; Shaw, Richard A.; Stanghellini, Letizia
We present the images of a Hubble Space Telescope (HST/WFC3) snapshot program of angularly compact Galactic planetary nebulae (PNe), acquired with the aim of studying their size, evolutionary status, and morphology. PNe that are smaller than ∼4″ are underrepresented in most morphological studies, and today they are less well studied than their imm…
Galactic Centre hypershell model for the North Polar Spurs
Kataoka, J.; Matsui, H.; Nakashima, S. +5 more
The bipolar-hypershell (BHS) model for the North Polar Spurs (NPS-E, -W, and Loop I) and counter southern spurs (SPS-E and -W) is revisited based on numerical hydrodynamical simulations. Propagations of shock waves produced by energetic explosive events in the Galactic Centre are examined. Distributions of soft X-ray brightness on the sky at 0.25,…
Classifying the embedded young stellar population in Perseus and Taurus and the LOMASS database
van Dishoeck, E. F.; Mottram, J. C.; Jørgensen, J. K. +3 more
Context. The classification of young stellar objects (YSOs) is typically done using the infrared spectral slope or bolometric temperature, but either can result in contamination of samples. More accurate methods to determine the evolutionary stage of YSOs will improve the reliability of statistics for the embedded YSO population and provide more r…
Searching for intermediate-mass black holes in globular clusters with gravitational microlensing
Kains, N.; Bramich, D. M.; Sahu, K. C. +1 more
We discuss the potential of the gravitational microlensing method as a unique tool to detect unambiguous signals caused by intermediate-mass black holes in globular clusters. We select clusters near the line of sight to the Galactic bulge and the Small Magellanic Cloud, estimate the density of background stars for each of them, and carry out simul…
The Star Formation Rate Efficiency of Neutral Atomic-dominated Hydrogen Gas in the Outskirts of Star-forming Galaxies from z ~ 1 to z ~3
Koekemoer, Anton M.; Gardner, Jonathan P.; Teplitz, Harry I. +5 more
Current observational evidence suggests that the star formation rate (SFR) efficiency of neutral atomic hydrogen gas measured in damped Lyα systems (DLAs) at z∼ 3 is more than 10 times lower than predicted by the Kennicutt-Schmidt (KS) relation. To understand the origin of this deficit, and to investigate possible evolution with redshift and galax…
Enhancement of a Sunspot Light Wall with External Disturbances
Yang, Shuhong; Zhang, Jun; Erdélyi, Robert
Based on the Interface Region Imaging Spectrograph observations, we study the response of a solar sunspot light wall to external disturbances. A flare occurrence near the light wall caused material to erupt from the lower solar atmosphere into the corona. Some material falls back to the solar surface and hits the light bridge (I.e., the base of th…
First Detection of a Pulsar Bow Shock Nebula in Far-UV: PSR J0437-4715
Pavlov, George G.; Kargaltsev, Oleg; Rangelov, Blagoy +3 more
Pulsars traveling at supersonic speeds are often accompanied by cometary bow shocks seen in Hα. We report on the first detection of a pulsar bow shock in the far-ultraviolet (FUV). We detected it in FUV images of the nearest millisecond pulsar J0437-4715 obtained with the Hubble Space Telescope. The images reveal a bow-like structure positionally …
The X-ray light curve of the massive colliding wind Wolf-Rayet + O binary WR 21a
Nazé, Yaël; Gosset, Eric
Our dedicated XMM-Newton monitoring, as well as archival Chandra and Swift datasets, were used to examine the behaviour of the WN5h+O3V binary WR 21a at high energies. For most of the orbit, the X-ray emission exhibits few variations. However, an increase in strength of the emission is seen before periastron, following a 1 /D relative trend, where…