The ACIS instrument on board the Chandra X-Ray Observatory has been used to carry out the first systematic study of low-mass X-ray binaries (LMXBs) in M 87 (NGC 4486), the giant elliptical galaxy near the dynamical center of the Virgo Cluster. These images - with a total exposure time of 154 ks - are the deepest X-ray observations obtained as of 2004 of M 87. The authors identified 174 X-ray point sources, (contained in this Browse table) of which ~ 150 are likely LMXBs. This LMXB catalog was combined with deep F475W and F850LP images taken with ACS on the Hubble Space Telescope (HST) (as part of the ACS Virgo Cluster Survey) to examine the connection between LMXBs and globular clusters in M87. Of the 1688 globular clusters in the authors' catalog, a fraction f_X = 3.6% +/- 0.5% contain an LMXB. M 87 (NGC 4486) was observed with the Chandra Advanced CCD Imaging Spectrometer (ACIS) for 121 ks on 2002 July 5-6. In this table, only the S3 chip data are used. The data were processed following the CIAO data reduction threads, including a correction for charge transfer inefficiency (CTI). In addition, the authors used 38 ks of archival ACIS observations of M 87 taken on 2000 July 29. These data were processed in a fashion similar to the 2002 July data, except that no CTI correction was possible because the data were telemetered in graded mode. All reductions were carried out with CIAO, version 2.3, coupled with CALDB, version 2.21. In order to combine the event files into a single image for point-source detection, the authors obtained relative offsets by matching the celestial coordinates of two X-ray point sources. The relative offset was ~ 0.5". The total exposure time of the co-added image, excluding four background flares totaling ~ 2.5 ks, was 154 ks. This table was created by the HEASARC in March 2007 based on the CDS table J/ApJ/613/279, file table1.dat. This is a service provided by NASA HEASARC .

ASASSN-14ko is a transient source in the ESO 253-G003 galaxy system, which is in the process of merging. It was discovered by the ASAS-SN survey in 2014, and it periodically flares in the optical every 114 days, with a period that is decreasing (Payne et al. 2021). This variability is likely due to multiple partial tidal disruption events involving a giant star orbiting the supermassive black hole in the northeastern galaxy of ESO 253-G003. The ESO 253-G003 system has been detected in radio by historic ASKAP and ATCA observations. The X-ray spectrum, the large gas fraction in the core region, based on the merging galaxy scenario and line diagnostics from MUSE observations, suggests that pTDE-triggered jet launching could explain the observed radio emission. VLBI observations will allow us to resolve the core region of the pTDE hosting AGN.

The Galactic Centre is the most complex and dynamic region of our Galaxy. Radio images have revealed a plethora of filamentary structures that trace out magnetic fields running perpendicular to the Galactic plane. Exactly what powers the radio emission of these filaments had remained a mystery, until the serendipitous discovery of a pulsar embedded in one. With a spin-period of 8.4 ms, PSR J1744-2946 is the first ever millisecond pulsar to be discovered in the central region of our Galaxy. While an exciting discovery in its own right, the limited timing baseline leaves open several unanswered questions: How efficiently is the pulsar injecting energy into the radio filament? Could the pulsar be included in pulsar timing array experiments? And can it be used as a key component in the search for axion dark matter? In this proposal we will use the Ultra-Wideband Low receiver system on Murriyang to conduct regular, monthly observations of PSR J1744-2946. This will provide us with a measurement of the pulsar spin-down rate and a sense of its long-term stability, thereby providing answers to the questions posed above.

We propose to search for temporal variations in HI absorption spectra seen against background pulsars to characterise Tiny Scale Atomic Structure (TSAS) in the Milky Way interstellar medium (ISM). We will re-observe seven previously studied bright pulsars at two observing epochs in this semester, resulting in minimum and maximum experimental baselines of 0.25 and 50 years. These observations will test predictions that there is a minimum size scale set by the thermal and turbulent properties of the ISM, below which TSAS is only sporadically seen, and will potentially provide the first direct measurements of pressures in "large" TSAS features of > 1000 AU. By using a new phase-resolved spectral line mode that we have recently implemented on Parkes, we will cut data rates and processing times by factors of ~1000. This project successfully observed in 2024APR and will be expanded to a Long Term Project when that scheme reopens for applications in 2025APR. Successful demonstration of our techniques will lay the groundwork for future programmes on the SKA.

Blazars are radio-loud active galactic nuclei whose jets point very close to the line of sight. High-resolution VLBI observations can provide the ultimate evidence for the blazar nature of a source, by revealing the compact, bright, high brightness temperature core with flat radio spectrum. Zywucka et al. (2018) selected the blazar candidates from the Magellanic Quasar Survey. The selection method based mainly on the optical variability and the radio-loudness of the sources. Using the infrared color-color selection for blazars derived from the data of the WISE satellite by Massaro et al. (2012) we found that 10 of the 27 WISE-detected sources are outside of the blazar gamma-ray strip. We propose to observe 7 sources from these list and additional 7 sources as a control sample which fall within the blazar strip. We want to compare the mas-scale properties of the two samples to asses whether (i) additional criteria is needed select blazar sources (ii) and if yes the WISE color-color criteria is able to improve the selection method. Optical emission and variability is thought to be dominated by the beamed jet in blazars while in non-beamed (and not radio-loud) sources it originates in the accretion disks thus governed by accretion processes. Therefore, if the physical mechanism causing the optical variability is intended to be studies the nature of the variable source is important to be ascertained.

We propose to search for temporal variations in HI absorption spectra seen against background pulsars to characterise Tiny Scale Atomic Structure (TSAS) in the Milky Way interstellar medium (ISM). We will re-observe seven previously studied bright pulsars at two observing epochs in this semester, resulting in minimum and maximum experimental baselines of 0.25 and 50 years. These observations will test predictions that there is a minimum size scale set by the thermal and turbulent properties of the ISM, below which TSAS is only sporadically seen, and will potentially provide the first direct measurements of pressures in "large" TSAS features of > 1000 AU. By using a new phase-resolved spectral line mode that we have recently implemented on Parkes, we will cut data rates and processing times by factors of ~1000. This project successfully observed in 2024APR and will be expanded to a Long Term Project when that scheme reopens for applications in 2025APR. Successful demonstration of our techniques will lay the groundwork for future programmes on the SKA.

We propose to search for temporal variations in HI absorption spectra seen against background pulsars to characterise Tiny Scale Atomic Structure (TSAS) in the Milky Way interstellar medium (ISM). We will re-observe seven previously studied bright pulsars at two observing epochs in this semester, resulting in minimum and maximum experimental baselines of 0.25 and 50 years. These observations will test predictions that there is a minimum size scale set by the thermal and turbulent properties of the ISM, below which TSAS is only sporadically seen, and will potentially provide the first direct measurements of pressures in "large" TSAS features of > 1000 AU. By using a new phase-resolved spectral line mode that we have recently implemented on Parkes, we will cut data rates and processing times by factors of ~1000. Following the success of this pilot project, we plan to expand to a long-term monitoring programme. Successful demonstration of our techniques will lay the groundwork for future programmes on the SKA.

We propose to search for temporal variations in HI absorption spectra seen against background pulsars to characterise Tiny Scale Atomic Structure (TSAS) in the Milky Way interstellar medium (ISM). We will re-observe seven previously studied bright pulsars at two observing epochs in this semester, resulting in minimum and maximum experimental baselines of 0.25 and 50 years. These observations will test predictions that there is a minimum size scale set by the thermal and turbulent properties of the ISM, below which TSAS is only sporadically seen, and will potentially provide the first direct measurements of pressures in "large" TSAS features of > 1000 AU. By using a new phase-resolved spectral line mode that we have recently implemented on Parkes, we will cut data rates and processing times by factors of ~1000. Following the success of this pilot project, we plan to expand to a long-term monitoring programme. Successful demonstration of our techniques will lay the groundwork for future programmes on the SKA.

We propose an LBA pilot phase-referenced observation at 8.4GHz of a pulsar J1638-4713 associated with a bow shock pulsar wind nebula. The estimated velocity of 1500 km/s for the driving pulsar, makes it potentially one of the fastest-moving pulsars. We propose this study in order to (i) derive a more accurate position for future VLBI epochs, (ii) determine the suitability of the source and phase-reference calibrator for subsequent multi-epoch studies to measure a proper motion, and possibly parallax, for this source and (iii) determine the milli-arcsecond scale structure of the source.