- ID:
- ivo://CDS.VizieR/J/AJ/154/252
- Title:
- A VLA survey of magnetic CVs. I. The data
- Short Name:
- J/AJ/154/252
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Jansky Very Large Array was used to observe 121 magnetic cataclysmic variables (MCVs). We report radio detections of 18 stars. Thirteen are new radio sources, increasing the number of MCVs that are radio sources by more than twofold, from 8 to 21. Most detections are at 8.7 GHz (X-band) with a lesser number at 5.4 and 21.1 GHz (C- and K-bands). With the exception of AE Aqr, whose flux density is typically >5 mJy, the flux densities are in the range of 24-780 {mu}Jy. Thirteen of the detections show highly circularly polarized emission, which is characteristic of electron-cyclotron maser emission. The data suggest that MCVs could possibly be divided into two classes of radio emitters: those dominated by weakly polarized gyrosynchrotron emission and those by highly polarized electron-cyclotron maser emission.
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- ID:
- ivo://CDS.VizieR/J/A+A/659/A145
- Title:
- A WISE view on extreme AGB stars
- Short Name:
- J/A+A/659/A145
- Date:
- 18 Mar 2022 08:25:03
- Publisher:
- CDS
- Description:
- Variability is a key property of stars on the asymptotic giant branch (AGB). Their pulsation period is related to the luminosity and mass-loss rate (MLR) of the star. Long-period variables (LPVs) and Mira variables are the most prominent of all types of variability of evolved stars. However, the reddest, most obscured AGB stars are too faint in the optical and have eluded large variability surveys. Our goal is to obtain a sample of LPVs with large MLRs by analysing WISE W1 and W2 light curves (LCs) for about 2000 sources, photometrically selected to include known C-stars with the 11.3 micron silicon carbide dust feature in absorption, and Galactic O-stars with periods longer than 1000 days. Epoch photometry was retrieved from the AllWISE and NEOWISE database and fitted with a sinus curve. Photometry from other variability surveys was also downloaded and fitted. For a subset of 316 of the reddest stars, spectral energy distributions (SEDs) were constructed, and, together with mid-infrared (MIR) spectra when available, fitted with a dust radiative transfer programme in order to derive MLRs. WISE based LCs and fits to the data are presented for all stars. Periods from the literature and periods from refitting other literature data are presented. The results of the spatial correlation with several (IR) databases is presented. About one-third of the sources are found to be not real, but it appears that these cannot be easily filtered out by using WISE flags. Some are clones of extremely bright sources, and in some cases the LCs show the known pulsation period. Inspired by a recent paper, a number of non-variable OH/IRs are identified. Based on a selection on amplitude, a sample of about 750 (candidate) LPVs is selected of which 145 have periods beyond 1000 days, many of them being new. For the subset of the stars with the colours of C-rich extremely red objects (EROs) the fitting of the SEDs (and available MIR spectra) separates them into C- and O-rich objects. Interestingly, the fitting of MIR spectra of mass-losing C-stars is shown to be a powerful tracer of interstellar reddening when AV larger than 2 mag. The number of Galactic EROs appears to be complete up to about 5 kpc and a total dust return rate in the solar neighbourhood for this class is determined. In the LMC 12 additional EROs are identified. Although this represents only about 0.15% of the total known LMC C-star population adding their MLRs increases the previously estimated dust return by 8%. Based on the EROs in the Magellanic Clouds, a bolometric period luminosity is derived. It is pointed out that due to their faintness, EROs and similar O-rich objects are ideal targets for a NIR version of Gaia to obtain distances, observing in the K-band or, even more efficiently, in the L-band.
1593. AWM 7 radial velocities
- ID:
- ivo://CDS.VizieR/J/AJ/116/2108
- Title:
- AWM 7 radial velocities
- Short Name:
- J/AJ/116/2108
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have measured redshifts and Kron-Cousins R-band magnitudes for a sample of galaxies in the poor cluster AWM 7. We have measured redshifts for 172 galaxies; 106 of these are cluster members. We determine the luminosity function (LF) from a photometric survey of the central 1.2x1.2h^-1^Mpc. The LF has a bump at the bright end and a faint-end slope of {alpha}=-1.37+/-0.16, populated almost exclusively by absorption-line galaxies. The cluster velocity dispersion is lower in the core (~530km/s) than at the outskirts (~680km/s), consistent with the cooling flow seen in the X-ray. The cold core extends ~150h^-1^kpc from the cluster center. The Kron-Cousins R-band mass-to-light ratio of the system is 650+/-170hM_{sun}_/L_{sun}_, substantially lower than previous optical determinations, but consistent with most previous X-ray determinations. We adopt H_0_=100hkm/s/Mpc throughout this paper; at the mean cluster redshift (5247+/-76km/s), 1h^-1^Mpc subtends 65.5'.
- ID:
- ivo://CDS.VizieR/J/A+AS/93/255
- Title:
- Axial ratios of edge-on spirals
- Short Name:
- J/A+AS/93/255
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- (no description available)
- ID:
- ivo://nasa.heasarc/axis
- Title:
- AXIS XMM-Newton Source Catalog
- Short Name:
- AXIS
- Date:
- 14 Feb 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- Recent results have revised upwards the total X-ray background (XRB) intensity below ~10 keV, therefore an accurate determination of the source counts is needed. There are also contradictory results on the clustering of X-ray selected sources. The authors have studied the X-ray source counts in four energy bands: soft (0.5 - 2 keV), hard (2 - 10 keV), XID (0.5 - 4.5 keV) and ultra-hard (4.5 - 7.5 keV) in order to evaluate the contribution of sources at different fluxes to the X-ray background. They have also studied the angular clustering of X-ray sources in those bands. AXIS (An XMM International Survey) is a survey of 36 high Galactic latitude XMM observations covering 4.8 square degrees in the Northern sky and containing 1433 serendipitous X-ray sources detected with 5-sigma significance. This survey has similar depth to the XMM catalogs and therefore serves as a pathfinder to explore their possibilities. The authors in their paper combined this survey with shallower and deeper surveys, and fitted the source counts with a Maximum Likelihood technique. Using only AXIS sources they studied the angular correlation using a novel robust technique. The AXIS source counts results are compatible with most previous samples in the soft, XID, ultra-hard and hard bands. This study has improved on previous results in the hard band. The fractions of the XRB resolved in the surveys used in this work are 87%, 85%, 60% and 25% in the soft, hard, XID and ultra-hard bands, respectively. Extrapolation of the source counts to zero flux is not sufficient to saturate the XRB intensity. Only galaxies and/or absorbed AGN could contribute the remaining unresolved XRB intensity. These results are compatible, within the errors, with recent revisions of the XRB intensity in the soft and hard bands. The maximum fractional contribution to the XRB comes from fluxes within about a decade of the break in the source counts (~10<sup>-14</sup> cgs), reaching ~50% of the total in the soft and hard bands. Angular clustering (widely distributed over the sky and not confined to a few deep fields) is detected at 99-99.9% significance in the soft and XID bands, with no detection in the hard and ultra-hard band (probably due to the smaller number of sources). The authors cannot confirm the detection of significantly stronger clustering in the hard-spectrum hard sources. Medium-depth surveys such as AXIS are essential to determine the evolution of the X-ray emission in the Universe below 10 keV. Included here are the basic data for the 2560 X-ray sources in the reference paper which satified the selection criteria of having an emldetect detection likelihood >= 10 (the default value) in at least one band, namely: (i) XMM-Newton pn count-rates in four XMM-Newton Science Analysis System (SAS) bands (band 2: 0.5 - 2 keV, band 3: 2 - 4.5 keV, band 4: 4.5 - 7.5 keV, band 5: 7.5 - 12 keV); (ii) spectral photon indices in the 0.5 - 4.5 keV band, the 2 - 10 keV band and the 0.5 - 10 keV band; (iii) fluxes in the soft (0.5 - 2 keV), hard (2 - 10 keV), XID (0.5 - 4.5 keV), ultra-hard (4.5 - 7.5 keV) and "total" (0.5 - 10 keV) bands; and (iv) flags describing to which of the samples discussed in the paper (soft, hard, XID or ultra-hard) each source belongs. There is no spectral or flux information given for the sources not belonging to any of the samples, but the count-rates of such sources are given for completeness. This table was created by the HEASARC in August 2007 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/A+A/469/27">CDS catalog J/A+A/469/27</a> file table23.dat. This is a service provided by NASA HEASARC .
- ID:
- ivo://CDS.VizieR/J/ApJS/187/388
- Title:
- A XMM-Newton survey of the SXRB
- Short Name:
- J/ApJS/187/388
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present measurements of the soft X-ray background (SXRB) OVII and OVIII intensity between l=120{deg} and l=240{deg}, the first results of a survey of the SXRB using archival XMM-Newton observations. We do not restrict ourselves to blank-sky observations, but instead use as many observations as possible, removing bright or extended sources by hand if necessary. In an attempt to minimize contamination from near-Earth solar wind charge exchange (SWCX) emission, we remove times of high solar wind proton flux from the data. Without this filtering we are able to extract measurements from 586 XMM-Newton observations. With this filtering, ~1/2 of the observations are rendered unusable, and we are able to extract measurements from 303 observations. The oxygen intensities are typically ~0.5-10 photons/cm^2^/s/sr (line units, L.U.) for OVII and ~0-5L.U. for OVIII. The proton flux filtering does not systematically reduce the oxygen intensities measured from a given observation. However, the filtering does preferentially remove the observations with higher oxygen intensities. Our data set includes 69 directions with multiple observations, whose oxygen intensity variations can be used to constrain SWCX models. After removing observations likely to be contaminated by heliospheric SWCX emission, we use our results to examine the Galactic halo.
- ID:
- ivo://CDS.VizieR/J/ApJ/484/394
- Title:
- AX Mon photometry and UV spectra
- Short Name:
- J/ApJ/484/394
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- AX Monocerotis is a 232d, noneclipsing, interacting binary star that consists of a K giant, a Be-like giant, and a large amounts of circumstellar material. The K star is almost certainly a synchronous rotator and is probably in contact with its critical lobe. The Be star was believed to be a rapid rotator based on extremely wide absorption lines, but new spectra show that these lines arise from the circumstellar environment. Hydrogen emission, also circumstellar, is many times stronger than the continuum. Near-ultraviolet light curves exhibit a 0.5 mag dip near phase 0.75, but there is no such variability at longer wavelengths. Gas flow trajectories from the cusp of the K star toward the Be star provide a simple explanation for the photometric and spectroscopic behavior. We may have found a decreasing orbital period, but more data are necessary to confirm this result. We present several models for AX Mon based on (1) new and archival visible photometry, (2) archival ultraviolet spectroscopy, (3) new and archival visible spectroscopy, (4) new visible polarimetry, and (5) new radio photometry. Further observations, including optical interferometry, are proposed.
1598. AX Per UBVRI photometry
- ID:
- ivo://CDS.VizieR/J/A+A/536/A27
- Title:
- AX Per UBVRI photometry
- Short Name:
- J/A+A/536/A27
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- AX Per is an eclipsing symbiotic binary. During active phases, deep narrow minima are observed in its light curve, and the ionization structure in the binary changes significantly. From ~2007.5, AX Per entered a new active phase. We aim to derive the ionization structure in the binary and its changes during the recent active phase. We used optical high- and low-resolution spectroscopy and UBVRcIc photometry. We modeled the SED in the optical and broad wings of the H alpha line profile during the 2007-10 higher level of the AX Per activity. After 10 orbital cycles (~18.6 years), we again measured the eclipse of the hot component by its giant companion in the light curve. We derived a radius of 27+/-2R_{sun}_ for the eclipsed object and 115+/-2R_{sun}_ for the eclipsing cool giant. The new active phase was connected with a significant enhancement of the hot star wind. From quiescence to activity, the mass-loss rate increased from ~9E-8 to ~3E-6M_{sun}_/yr, respectively. The wind causes the emission of the He++ zone, located in the vicinity of the hot star, and also is the reason for the fraction of the [OIII] zone at farther distances. Simultaneously, we identified a variable optically thick warm (T_eff_~6000K) source that contributes markedly to the composite spectrum. The source was located at the hot star's equator and has the form of a flared disk, whose outer rim simulates the warm photosphere. The formation of the neutral disk-like zone around the accretor during the active phase was connected with its enhanced wind. It is probable that this connection represents a common origin of the warm pseudophotospheres that are indicated during the active phases of symbiotic stars.
- ID:
- ivo://CDS.VizieR/J/ApJ/876/49
- Title:
- A 10yr reverberation mapping campaign for 3C273
- Short Name:
- J/ApJ/876/49
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Despite many decades of study, the kinematics of the broad-line region of 3C 273 are still poorly understood. We report a new, high signal-to-noise, reverberation mapping campaign carried out from 2008 November to 2018 March that allows the determination of time lags between emission lines and the variable continuum with high precision. The time lag of variations in H{beta} relative to those of the 5100{AA} continuum is 146.8_-12.1_^+8.3^days in the rest frame, which agrees very well with the Paschen-{alpha} region measured by the GRAVITY at The Very Large Telescope Interferometer. The time lag of the H{gamma} emission line is found to be nearly the same as that for H{beta}. The lag of the FeII emission is 322.0_-57.9_^+55.5^days, longer by a factor of ~2 than that of the Balmer lines. The velocity-resolved lag measurements of the H{beta} line show a complex structure that can be possibly explained by a rotation-dominated disk with some inflowing radial velocity in the H{beta}-emitting region. Taking the virial factor of f_BLR_=1.3, we derive a BH mass of dM/dt=4.1_-0.4_^+0.3^x10^8^M_{sun}_ and an accretion rate of 9.3L_Edd_c^-2^ from the H{beta} line. The decomposition of its Hubble Space Telescope images yields a host stellar mass of M*=10^11.3+/-0.7^M_{sun}_, and a ratio of dM/dt/M*~2.0x10^-3^ in agreement with the Magorrian relation. In the near future, it is expected to compare the geometrically thick BLR discovered by the GRAVITY in 3C 273 with its spatially resolved torus in order to understand the potential connection between the BLR and the torus.
- ID:
- ivo://CDS.VizieR/J/A+A/618/A121
- Title:
- Azimuthal anistropy of stellar galactic disks
- Short Name:
- J/A+A/618/A121
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The ellipsoid of stellar random motions is a fundamental ingredient of galaxy dynamics. Yet it has long been difficult to constrain this component in disks others than the Milky Way. This article presents the modeling of the azimuthal-to-radial axis ratio of the velocity ellipsoid of galactic disks from stellar dispersion maps using integral field spectroscopy data of the CALIFA survey. The measured azimuthal anisotropy is shown to be not strongly dependent on the assumed vertical-to-radial dispersion ratio of the ellipsoid. The anisotropy distribution shows a large diversity in the orbital structure of disk galaxies from tangential to radial stellar orbits. Globally, the orbits are isotropic in inner disk regions and become more radial as a function of radius, although this picture tends to depend on galaxy morphology and luminosity. The Milky Way orbital anisotropy profile measured from the Second Gaia Data Release is consistent with those of CALIFA galaxies. A new correlation is evidenced, linking the absolute magnitude or stellar mass of the disks to the azimuthal anisotropy. More luminous disks have more radial orbits and less luminous disks have isotropic and somewhat tangential orbits. This correlation is consistent with the picture in galaxy evolution in which orbits become more radial as the mass grows and is redistributed as a function of time. With the help of circular velocity curves, it is also shown that the epicycle theory fails to reproduce the diversity of the azimuthal anisotropy of stellar random motions, as it predicts only nearly radial orbits in the presence of flat curves. The origin of this conflict is yet to be identified. It also questions the validity of the vertical-to-radial axis ratio of the velocity ellipsoid derived by many studies in the framework of the epicyclic approximation.
