V405 Peg (RBS 1955): A Nearby, Low-Luminosity Cataclysmic Binary

(Abridged). The cataclysmic binary V405 Peg, originally discovered as ROSAT Bright Source (RBS) 1955 (= 1RXS J230949.6+213523), shows a strong contribution from a late-type secondary star in its optical spectrum, which led Schwope et al. to suggest it to be among the nearest cataclysmic binaries. We present extensive optical observations of V405 Peg. Time-series spectroscopy shows the orbital period, Porb, to be 0.1776469(7) d (= 4.2635 hr), or 5.629 cycle/d. We classify the secondary as M3 - M4.5. Astrometry with the MDM 2.4m telescope gives a parallax 7.2 +- 1.1 milli-arcsec, and a relative proper motion of 58 mas/yr. Our best estimate of the distance yields d = 149 (+26, -20) pc. The secondary stars's radial velocity has K2 = 92 +- 3 km/s, indicating a fairly low orbital inclination if the masses are typical. Extensive I-band time-series observations in the show the system varying between a minimum brightness level of I = 14.14 and states of enhanced activity about 0.2 mag brighter. While the low-state shows an ellipsoidal modulation, an additional photometric modulation appears in the high state, with 0.1 mag amplitude and period 220-280 min. The frequency of this modulation appears to be stable for a month or so, but no single period was consistently detected from one observing season to the next. We estimate the system luminosity by combining optical measurements with the archival X-ray spectrum. The implied mass accretion rate is orders of magnitudes below the predictions for the standard angular momentum loss above the period gap. The system may possibly belong to a largely undiscovered population of hibernating CVs.Comment: 11 figures; 7 of these are .png or .jpg to save space. In press for Publications of the Astronomical Society of the Pacifi

The changing accretion states of the intermediate polar MU Camelopardalis

We study the timing and spectral properties of the intermediate polar MU Camelopardalis (1RXS J062518.2+733433) to determine the accretion modes and the accretion geometry from multi-wavelength, multi-epoch observational data. Light curves in different observed energy ranges (optical, UV, X-ray) are extracted. The timescales of variability in these light curves are determined using Analysis of Variance. Phase-resolved X-ray spectra are created with respect to the most prominent detected periodicities and each fitted with an identical model, to quantify the differences in the fitted components. The published tentative value for the spin period is unambiguously identified with the rotation period of the white dwarf. We detect a distinct soft X-ray component that can be reproduced well by a black body. The analysis of data obtained at different epochs demonstrates that the system is changing its accretion geometry from disk-dominated to a combination of disk- plus stream-dominated, accompanied with a significant change in brightness at optical wavelengths.Comment: Accepted for publication in Astron. Astrophys., 13 pages, 10 figure

Masses of the components of SB2 binaries observed with Gaia. II. Masses derived from PIONIER interferometric observations for Gaia validation

In anticipation of the Gaia astrometric mission, a sample of spectroscopic binaries is being observed since 2010 with the Sophie spectrograph at the Haute--Provence Observatory. Our aim is to derive the orbital elements of double-lined spectroscopic binaries (SB2s) with an accuracy sufficient to finally obtain the masses of the components with relative errors as small as 1 % when combined with Gaia astrometric measurements. In order to validate the masses derived from Gaia, interferometric observations are obtained for three SB2s in our sample with F-K components: HIP 14157, HIP 20601 and HIP 117186. The masses of the six stellar components are derived. Due to its edge-on orientation, HIP 14157 is probably an eclipsing binary. We note that almost all the derived masses are a few percent larger than the expectations from the standard spectral-type-mass calibration and mass-luminosity relation. Our calculation also leads to accurate parallaxes for the three binaries, and the Hipparcos parallaxes are confirmed.Comment: 10 pages, 3 figures, accepted by MNRA

Post common envelope binaries from the SDSS VI. SDSS J120615.73+510047.0 : a new low accretion rate magnetic binary

We report the discovery of the ninth pre-polar consisting of a late-type ZAMS secondary and a magnetic white dwarf. The white dwarf accretes at an extreme low rate, \dot{M} \sim 10^ $M_\odot$ yr-1, from the wind of the companion donor star. The source was found in our systematic search for WD/MS binaries within SDSS/SEGUE. Based on seven Sloan spectra we estimate a binary period of ~200, 230, or 270 min. The UV to IR spectral energy distribution was decomposed into a dM3-dM4 ZAMS secondary and a cool white dwarf, ~9000 K, which consistently imply a distance between 360 and 420 pc. The optical spectrum displays one pronounced cyclotron hump, likely originating from a low-temperature plasma, ~1 keV, in a field of 108 MG. We comment on the evolutionary link between polars and pre-polars

The XMM-Newton serendipitous survey. VII. The third XMM-Newton serendipitous source catalogue

Thanks to the large collecting area (3 x ~1500 cm$^2$ at 1.5 keV) and wide field of view (30' across in full field mode) of the X-ray cameras on board the European Space Agency X-ray observatory XMM-Newton, each individual pointing can result in the detection of hundreds of X-ray sources, most of which are newly discovered. Recently, many improvements in the XMM-Newton data reduction algorithms have been made. These include enhanced source characterisation and reduced spurious source detections, refined astrometric precision, greater net sensitivity and the extraction of spectra and time series for fainter sources, with better signal-to-noise. Further, almost 50\% more observations are in the public domain compared to 2XMMi-DR3, allowing the XMM-Newton Survey Science Centre (XMM-SSC) to produce a much larger and better quality X-ray source catalogue. The XMM-SSC has developed a pipeline to reduce the XMM-Newton data automatically and using improved calibration a new catalogue version has been produced from XMM-Newton data made public by 2013 Dec. 31 (13 years of data). Manual screening ensures the highest data quality. This catalogue is known as 3XMM. In the latest release, 3XMM-DR5, there are 565962 X-ray detections comprising 396910 unique X-ray sources. For the 133000 brightest sources, spectra and lightcurves are provided. For all detections, the positions on the sky, a measure of the quality of the detection, and an evaluation of the X-ray variability is provided, along with the fluxes and count rates in 7 X-ray energy bands, the total 0.2-12 keV band counts, and four hardness ratios. To identify the detections, a cross correlation with 228 catalogues is also provided for each X-ray detection. 3XMM-DR5 is the largest X-ray source catalogue ever produced. Thanks to the large array of data products, it is an excellent resource in which to find new and extreme objects.Comment: 23 pages, version accepted for publication in A&

VizieR Online Data Catalog: XMM-Newton Serendipitous Source Catalogue 3XMM-DR5 (XMM-SSC, 2016)

The 3XMM-DR5 catalogue is the third generation catalog of serendipitous X-ray sources from the European Space Agency's (ESA) XMM-Newton observatory, and has been created by the XMM-Newton Survey Science Centre (SSC) on behalf of ESA. The catalog has 354 more observations and 34701 more detections than the preceding 3XMM-DR4 catalog, which was made public in July 2013. The history of the versions can be summarized as: ------------ Name DR# Designation Year Cat. #Sources 2XMMp 0 2XMMp-DR0 2006 2XMM 1 2XMM-DR1 2007 IX/39 191870 2XMMi 2 2XMMi-DR2 2008 IX/40 221012 2XMMi-DR3 3 2XMMi-DR3 2010 IX/41 262902 3XMM-DR4 4 3XMM 2013 IX/44 372728 3XMM-DR5 5 3XMM 2016 IX/46 396910 The production and content of the 3XMM catalogue is described in the the 3XMM-DR4 User Guide at http://xmmssc.irap.omp.eu/Catalogue/3XMM-DR5/3XMM-DR5CatalogueUser_Guide.html The "slim" version of the catalogue (file "xmm3r5s.dat") contains one row per unique source, while the the main catalogue has one row per detection. This slim version includes 44 columns, essentially those containing information about the unique sources, while the full catalogue (file "xmm3r5.fit") describes all detections with 323 columns. The slim version also contains a column with links to the summary pages in the IRAP catalogue archive. In the case of sources with multiple detections the summary page of the best detection is selected (i.e., the detection with the largest exposure time, summed over all cameras), and the summary page gives cross-links to the other detections. A separate file "summary.dat" contains the key details about the observations used in the construction of the 3XMM-DR5 catalogue. (3 data files)

VizieR Online Data Catalog: XMM-Newton Serendipitous Source Catalogue 3XMM-DR6 (XMM-SSC, 2016)

The 3XMM-DR6 catalogue contains source detections drawn from 9160 XMM-Newton EPIC observations, covering an energy interval from 0.2keV to 12keV. These observations were made between 2000 February 3 and 2015 June 4 and all datasets were publicly available by 2016 January 31, but not all public observations are included in this catalogue (see below for more information). Should you use the catalogue for your research and publish the results, please use the acknowledgement below and cite the paper describing 3XMM (Rosen, Webb, Watson et al., 2016A&A...590A...1R). This research has made use of data obtained from the 3XMM XMM-Newton serendipitous source catalogue compiled by the 10 institutes of the XMM-Newton Survey Science Centre selected by ESA. The following table gives an overview of the statistics of the catalogue in comparison with the 3XMM-DR4 catalogue. - 3XMM-DR6 3XMM-DR5 Increment Number of observations 9160 7781 1379 Number of 'clean' observations (i.e., observation class =1ks exposure) 982sq.deg 877sq.deg 105sq.deg Number of detections 678680 565962 112718 Number of 'clean' detections (i.e., summary flag -5 5238 4668 570 .The production and content of the 3XMM catalogue is described in the the 3XMM-DR6 User Guide at http://xmmssc.irap.omp.eu/Catalogue/3XMM-DR6/3XMM-DR6CatalogueUser_Guide.html The "slim" version of the catalogue (file "xmm3r6s.dat") contains one row per unique source, while the the main catalogue has one row per detection. This slim version includes 44 columns, essentially those containing information about the unique sources, while the full catalogue (file "xmm3r6.fit") describes all detections with 323 columns. The slim version also contains a column with links to the summary pages in the IRAP catalogue archive. In the case of sources with multiple detections the summary page of the best detection is selected (i.e., the detection with the largest exposure time, summed over all cameras), and the summary page gives cross-links to the other detections. A separate file "summary.dat" contains the key details about the observations used in the construction of the 3XMM-DR6 catalogue. (3 data files)