Three X-ray Transients in M31 Oberserved with Swift

Aims.The purpose of this study is to find transient X-ray sources in M 31, and to investigate and classify their nature.Methods.Three X-ray transients were observed with Swift. For each of the three X-ray transients we use the Swift X-ray and opticaldata together with observations from XMM-Newton and Chandra to investigate the lightcurves and the spectra of the outburst, andthereby to identify the source types. Results.The outburst of XMMU J004215.8+ 411924 lasted for about one month. The source had a hard power-law spectrum with aphoton index of 1.6. It was previously identified as a Be/X-ray binary based on the optical identification with a star. However, we showthat with improved source coordinates it is clear that the optical source is not the counterpart to the X-ray source. The source SWIFTJ004217.3+ 411532 had a bright outburst, after which it slowly decayed over half a year. The spectrum was soft, corresponding to athermal accretion disk with innermost temperature of ∼ 250 − 600 eV. The source was not seen in the optical, and the soft spectrumindicates that the source is most likely a black hole low mass X-ray binary. M31N 2006-11a is a nova that was previously observed inthe optical. We detected it both in X-rays and UV with Swift ∼ half a year after the optical maximum, after which it decayed below theSwift detection threshold within a month. The spectrum of the X-ray transient can be modelled by a black-body with a temperature of50 eV. We use catalogues of X-ray transients in M 31 to estimate their rate, and we find a lower limit of 9 yr−

X-Ray Source Variability Study of the M31 Central Field Using Chandra HRC-1

Context. The central field of the Andromeda galaxy (M 31) has been monitored, using the Chandra HRC-I detector (about 0.1-10 keV energy range) from 2006 to 2012 with the main aim to detect X-rays from optical novae. We present a systematic analysis of all X-ray sources found in the 41 nova monitoring observations, along with 23 M 31 central field HRC-I observations available from the Chandra data archive starting in December 1999. Aims. Based on these observations, we studied the X-ray long-term variability of the source population and especially of X-ray binaries in M 31. Methods. We created a catalogue of sources, detected in the 64 available observations, which add up to a total exposure of about 1 Ms. To study the variability, we developed a processing pipeline to derive long-term Chandra HRC-I light curves for each source over the 13 years of observations. In the merged images we also searched for extended X-ray sources. Results. We present a point-source catalogue, containing 318 X-ray sources with detailed long-term variability information. 28 of which are published for the first time. The spatial and temporal resolution of the catalogue allows us to classify 115 X-ray binary candidates showing high X-ray variability or even outbursts in addition to 14 globular cluster X-ray binary candidates showing no significant variability. The analysis may suggest, that outburst sources are less frequent in globular clusters than in the field of M 31. We detected 7 supernova remnants, one of which is a new candidate and in addition resolved the first X-rays from a known radio supernova remnant. Besides 33 known optical nova/X-ray source correlations, we also discovered one previously unknown super-soft X-ray outburst and several new nova candidates. Conclusions. The catalogue contains a large sample of detailed long-term X-ray light curves in the M 31 central field, which helps to understand the X-ray population of our neighbouring spiral galaxy M 31

Supersoft X-rays Reveal a Classical Nova in the M31 Globular Cluster Bol 126

Context. Classical novae (CNe) represent the main class of supersoft X-ray sources (SSSs) in the central region of our neighbouring galaxy M 31. Only three confirmed novae and three SSSs have been discovered in globular clusters (GCs) of any galaxy so far, of which one nova and two SSSs (including the nova) were found in M 31 GCs. Aims. To study the SSS state of CNe we carried out a high-cadence X-ray monitoring of the M 31 central area with XMM-Newton and Chandra. This project is supplemented by regular optical monitoring programmes at various observatories. Methods. We analysed X-ray and optical monitoring data of a new transient X-ray source in the M 31 GC Bol 126, discovered serendipitously in Swift observations. Our optical data set was based on regular M 31 monitoring programmes from five different small telescopes and was reduced using a homogeneous method. Additionally, we made use of Pan-STARRS 1 data obtained during the PAndromeda survey. We extracted light curves of the source in the optical and X-rays, as well as X-ray spectra. Results. Our observations reveal that the X-ray source in Bol 126 is the third SSS in an M 31 GC and can be confirmed as the sec-ond CN in the M 31 GC system. This nova is named M31N 2010-10f. Its properties in the X-ray (high black-body temperature, short SSS phase) and optical (relatively high maximum magnitude, fast decline) regimes agree with a massive white dwarf (MWD 1.3 M) in the binary system. Incorporating the data on previously found (suspected) novae in M 31 GCs we used our high-cadence X-ray monitoring observations to estimate a tentative nova rate in the M 31 GC system of 0.05 yr−1 GC−1. An optical estimate, based on the recent 10.5-year WeCAPP survey, gives a lower nova rate, which is compatible with the X-ray rate on the 95% confidence level. Conclusions. Although still based on small-number statistics, there is growing evidence that the nova rate in GCs is higher than ex-pected from primordial binary formation and under conditions as in the field. Dynamical binary formation and/or additional accretion from the intracluster medium are possible scenarios for an increased nova rate, but observational confirmation for this enhancement has been absent, so far. Regular X-ray monitoring observations of M 31 provide a promising strategy to find these novae

X-Ray Monitoring of Classical Novae in the Central Region of M31. I. June 2006 - March 2007

Context. Classical novae (CNe) have recently been reported to represent the major class of supersoft X-ray sources (SSSs) in the central region of our neighbour galaxy M 31. Aims. We carried out a dedicated monitoring of the M 31 central region with XMM-Newton and Chandra in order to find SSS coun-terparts of CNe, determine the duration of their SSS phase and derive physical outburst parameters. Methods. We systematically searched our data for X-ray counterparts of CNe and determined their X-ray light curves and spectral properties. Additionally, we determined luminosity upper limits for all novae from previous studies which are not detected anymore and for all CNe in our field of view with optical outbursts between May 2005 and March 2007. Results. We detected eight X-ray counterparts of CNe in M 31, four of which were not previously known. Seven sources can be classified as SSSs, one is a candidate SSS. Two SSSs are still visible more than nine years after the nova outburst, whereas two other nova counterparts show a short SSS phase of less than 150 days. Of the latter sources, M31N 2006-04a exhibits a short-time variable X-ray light curve with an apparent period of (1.6 ±0.3) h. This periodicity could indicate the binary period of the system. There is no X-ray detection for 23 out of 25 CNe which were within the field of view of our observations and had their outburst from about one year before the start of the monitoring until its end. From the 14 SSS nova counterparts known from previous studies, ten are not detected anymore. Additionally, we found four SSSs in our XMM-Newton data without a nova counterpart, one of which is a new source. Conclusions. Out of eleven SSSs detected in our monitoring, seven are counterparts of CNe. We therefore confirm the earlier finding that CNe are the major class of SSSs in the central region of M 31. We use the measured SSS turn-on and turn-offtimes to estimate the mass ejected in the nova outburst and the mass burned on the white dwarf. Classical novae with short SSS phases seem to be an important contributor to the overall population

Deep XMM-Newton observations of the northern disk of M31 II: Tracing the hot interstellar medium

Aims: We use new deep XMM-Newton observations of the northern disk of M 31 to trace the hot interstellar medium (ISM) in unprecedented detail and to characterise the physical properties of the X-ray emitting plasmas. Methods: We used all XMM-Newton data up to and including our new observations to produce the most detailed image yet of the hot ISM plasma in a grand design spiral galaxy such as our own. We compared the X-ray morphology to multi-wavelength studies in the literature to set it in the context of the multi-phase ISM. We performed spectral analyses on the extended emission using our new observations as they offer sufficient depth and count statistics to constrain the plasma properties. Data from the Panchromatic Hubble Andromeda Treasury were used to estimate the energy injected by massive stars and their supernovae. We compared these results to the hot gas properties. Results: The brightest emission regions were found to be correlated with populations of massive stars, notably in the 10 kpc star-forming ring. The plasma temperatures in the ring regions are ~0.2 keV up to ~0.6 keV. We suggest this emission is hot ISM heated in massive stellar clusters and superbubbles. We derived X-ray luminosities, densities, and pressures for the gas in each region. We also found large extended emission filling low density gaps in the dust morphology of the northern disk, notably between the 5 kpc and 10 kpc star-forming rings. We propose that the hot gas was heated and expelled into the gaps by the populations of massive stars in the rings. Conclusions. It is clear that the massive stellar populations are responsible for heating the ISM to X-ray emitting temperatures, filling their surroundings, and possibly driving the hot gas into the low density regions. Overall, the morphology and spectra of the hot gas in the northern disk of M 31 is similar to other galaxy disks.Comment: 23 pages, 14 figures, accepted for publication in Astronomy & Astrophysic

Chandra ACIS Survey of M33 (ChASeM33): A First Look

We present an overview of the Chandra ACIS Survey of M33 (ChASeM33): A Deep Survey of the Nearest Face-on Spiral Galaxy. The 1.4 Ms survey covers the galaxy out to R \approx 18\arcmin (\approx 4 kpc). These data provide the most intensive, high spatial resolution assessment of the X-ray source populations available for the confused inner regions of M33. Mosaic images of the ChASeM33 observations show several hundred individual X-ray sources as well as soft diffuse emission from the hot interstellar medium. Bright, extended emission surrounds the nucleus and is also seen from the giant \hii regions NGC 604 and IC 131. Fainter extended emission and numerous individual sources appear to trace the inner spiral structure. The initial source catalog, arising from $\sim$~2/3 of the expected survey data, includes 394 sources significant at the $3\sigma$ confidence level or greater, down to a limiting luminosity (absorbed) of $\sim$1.6\ergs{35} (0.35 -- 8.0 keV). The hardness ratios of the sources separate those with soft, thermal spectra such as supernova remnants from those with hard, non-thermal spectra such as X-ray binaries and background active galactic nuclei. Emission extended beyond the Chandra point spread function is evident in 23 of the 394 sources. Cross-correlation of the ChASeM33 sources against previous catalogs of X-ray sources in M33 results in matches for the vast majority of the brighter sources and shows 28 ChASeM33 sources within 10\arcsec of supernova remnants identified by prior optical and radio searches. This brings the total number of such associations to 31 out of 100 known supernova remnants in M33.Comment: accepted for publication ApJS, full resolution images and complete tables available at http://hea-www.harvard.edu/vlp_m33_public

Boundary layer emission and Z-track in the color-color diagram of luminous LMXBs

We demonstrate that Fourier-frequency resolved spectra of atoll and Z- sources are identical, despite significant difference in their average spectra and luminosity (by a factor of ~10-20). This result fits in the picture we suggested earlier, namely that the f> 1 Hz variability in luminous LMXBs is primarily due to variations of the boundary layer luminosity. In this picture the frequency resolved spectrum equals the boundary layer spectrum, which therefore can be straightforwardly determnined from the data. The obtained so boundary layer spectrum is well approximated by the saturated Comptonization model, its high energy cut-off follows kT~2.4 keV black body. Its independence on the global mass accretion rate lends support to the theoretical suggestion by Inogamov &Sunyaev (1999) that the boundary layer is radiation pressure supported. With this assumption we constrain the gravity on the neutron star surface and its mass and radius. Equipped with the knowledge of the boundary layer spectrum we attempt to relate the motion along the Z-track to changes of physically meaningful parameters. Our results suggest that the contribution of the boundary layer to the observed emission decreases along the Z-track from conventional ~50% on the horizontal branch to a rather small number on the normal branch. This decrease can be caused, for example, by obscuration of the boundary layer by the geometrically thick accretion disk at Mdot ~ Mdot_Edd. Alternatively, this can indicate significant change of the structure of the accretion flow at Mdot ~ Mdot_ Edd and disappearance of the boundary layer as a distinct region of the significant energy release associated with the neutron star surface.Comment: 9 pages, 7 figures, Accepted in A&

Organs and organ builders in Regensburg (Germany). The „Regensburgisches Diarium“ from 1760 to 1810 as a source of organ building historical aspects

The Regensburg organ life in the second half of the 18th century and at the beginning of the 19th century is characterized by a surprisingly large variety. The playing and the building of organs and the organ trade have left clear traces in the Regensburg newspapers (“Regensburgisches Diarium”, “Regensburgische Frag- und Anzeige-Nachrichten” and “Kurfürstlich Erzkanzlerisches Regierungs- und Intelligenzblatt”). Organ music did not only take place in the Regensburg sacred buildings, but was also played on numerous verifiable house and chamber organs in the private houses and apartments of different social classes. Advertisements of about 40 organ instruments were documented during the reporting period. The domestic organ playing seems to have fulfilled a function in Regensburg at the end of the 18th century, which was replaced by the piano at the beginning of the 19th century. This large base of organ playing in Regensburg promoted the construction of organ positivs and house organs in different sizes (with up to three manuals and pedal) by the local organ builders. During their travels, numerous organ builders stayed as guests in Regensburg. The Regensburg and Regensburg-Stadtamhof-based organ builder families Herberger, Mälzel, Schmahl und Späth are documented with numerous entries in the “Diarium”. Both, the company and family stories of the individual organ building workshops like the contacts between local and traveling organ builders were extensively documented by newspaper reports. Especially the story of the famous Regensburg workshop Späth-Schmahl could be supplemented by the “Diariums” data to new findings. Also the knowledge of the organ and instrument maker family Mälzel and her best known son, the so-called metronome inventor Johann Nepomuk Mälzel the younger was augmented with important facts. The present evaluation of the organ-specific aspects of the “Regensburg Diarium” sees itself as a music-historical basic research for the local, regional as well as the national area. It would like to provide data and facts for later constructive research, well-founded starting point for new research approaches, detailed knowledge of the current state of research and reliable corrective of older researches

RUCH TRANSFEROWY MIĘDZY EUROPĄ ŚRODKOWO-WSCHODNIĄ A ZACHODNIMI OŚRODKAMI MUZYKI KOŚCIELNEJ W RATYZBONIE, WE WIEDNIU I W RZYMIE OD XVIII DO XX WIEKU

Rozwój muzyki kościelnej od stuleci przebiega w oparciu o centra, które wyznaczają jego kierunki. Od XVII do XX w. ośrodkami, które skupiały na sobie szczególną uwagę katolicyzmu (choć także protestantyzmu), w obszarze muzyki kościelnej były Ratyzbona, Wiedeń i Rzym. Artykuł omawia wymianę „ideową” w muzyce kościelnej, jaka dokonywała się pomiędzy tymi centrami a Europą Środkowo-Wschodnią. Autor prowadzi swoją refleksję, wyznaczając następujące części w swoim artykule: (1) rzymscy kapelmistrzowie na dworze królów polskich; (2) długa koegzystencja stile antico i stile moderno w katolickiej muzyce kościelnej w XVII i XVIII w.; (3) Carl Proske, pochodzący ze Śląska, a reforma muzyki w katedrze ratyzbońskiej; (4) członkowie z Europy Środkowo-Wschodniej w stowarzyszeniu cecyliańskim Franza Xavera Witta; (5) studenci w ratyzbońskiej Szkole Muzyki Kościelnej Franza Xavera Haberla z Europy Środkowo-Wschodniej; (6) A. de Santi oraz L. Perosi jako reformatorzy katolickiej muzyki kościelnej we Włoszech