The Radio Structure of the Supernova Remnant MSH14-63

G315.4-2.3 is an extended shell supernova remnant (SNR) with some characteristics of evolutionarily young remnants and some of older ones. To further elucidate some of its characteristics, we present imaging and polarimetry of this SNR at a frequency of 1.34 GHz with a resolution of 8 arcsec made with the Australia Telescope Compact Array. The indicators of youth are: Morphologically, the radio emission arises in a smooth shell without the fine scale filaments seen in the optical. Many of the optical filaments are Balmer dominated. Where measurable, the orientation of the magnetic field appears to be radial with respect to the center of the remnant. There may have been a supernova in that region in AD185. Indications of older age include: Particularly in RCW86, the bright optical nebula in the southwestern corner of this extended SNR, but also in other locations there are several filaments with bright [S II] emission representative of older shocked filaments in radiative equilibrium. If the remnant lies at the kinematical distance of 2.8 kpc, it has a diameter of 37 pc which would be large for a remnant less than two thousand years old. The remnant seems to be expanding inside a cavity outlined by infrared emission and so it could well be young and large. Where it is encountering the walls of the cavity it is slowing rapidly and we observe the radiative filaments. RCW86 itself is encountering a dense clump of material but may also be the remains of a more compact lump of ejecta ploughing into the surroundings.Comment: 15 pages in AAS LaTeX 5.0, 5 figures (2 parts in JPEG, 6 in GIF, 4 in eps), accepted by Ap

Binary and Millisecond Pulsars at the New Millennium

We review the properties and applications of binary and millisecond pulsars. Our knowledge of these exciting objects has greatly increased in recent years, mainly due to successful surveys which have brought the known pulsar population to over 1300. There are now 56 binary and millisecond pulsars in the Galactic disk and a further 47 in globular clusters. This review is concerned primarily with the results and spin-offs from these surveys which are of particular interest to the relativity community.Comment: 59 pages, 26 figures, 5 tables. Accepted for publication in Living Reviews in Relativity (http://www.livingreviews.org

Multi-messenger observations of a binary neutron star merger

On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ~1.7 s with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of 40+8-8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 Mo. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ~40 Mpc) less than 11 hours after the merger by the One- Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ~10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ~9 and ~16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta

Multi-messenger Observations of a Binary Neutron Star Merger

On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ∼ 1.7 {{s}} with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of {40}-8+8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 {M}ȯ . An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ∼ 40 {{Mpc}}) less than 11 hours after the merger by the One-Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ∼10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ∼ 9 and ∼ 16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC 4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta.</p

The HIZOA-S survey

VizieR online Data Catalogue associated with article published in journal Astronomical Journal (AAS) with title 'The Parkes H I zone of avoidance survey.' (bibcode: 2016AJ....151...52S

The soft X-ray properties of a complete sample of radio sources

We present the soft X-ray (0.1-2.4 keV) properties of a complete sample of 88 southern radio sources derived from the Wall and Peacock 2-Jy sample. It comprises 68 radio galaxies, 18 quasars and 2 BL Lac objects. Whereas both BL Lac objects and all but one quasar are detected in the ROSAT All-Sky Survey, the fraction of detected radio galaxies is only #approx# 60%. For the undetected sources upper limits to the X-ray flux are given. We confirm the correlation of the soft X-ray luminosity (L_x) with the core radio luminosity (L_r,_c_o_r_e) for galaxies as well as for quasars using partial correlation analysis, whereas the corresponding correlations between L_x and L_r,_t_o_t_a_l are probably spurious due to sample selection effects. We also find strong correlations between L_x and L_r,_c_o_r_e for both Fanaroff-Riley type I (FR I) and type II galaxies. The broad line radio galaxies (BLRG) and the quasars are at the top end of the X-ray luminosity distribution and the detection rate of these objects generally is higher than that of the narrow or weak lined radio galaxies. This indicates the presence of an anisotropic X-ray component in BLRG and quasars, as predicted by unified schemes for radio sources. (orig.)Available from TIB Hannover: RN 9303(343) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman