- ID:
- ivo://CDS.VizieR/J/MNRAS/448/3766
- Title:
- INTEGRAL 11-year hard X-ray survey
- Short Name:
- J/MNRAS/448/3766
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of an all-sky survey, performed with data acquired by the Imager on-Board the INTEGRAL Satellite (IBIS) telescope on board the INTErnational Gamma-Ray Astrophysics Laboratory (INTEGRAL) observatory over 11 years of operation, at energies above 100 keV. The catalogue of detected sources includes 132 objects. The statistical sample detected on the time-averaged 100-150 keV map at a significance above 5{sigma} contains 88 sources: 28 active galactic nuclei (AGNs), 38 low-mass X-ray binaries (LMXBs), 10 high-mass X-ray binaries (HMXBs) and 12 rotation-powered young X-ray pulsars. The catalogue also includes 15 persistent sources, which were registered at significance 4{sigma}<=S/N<5{sigma}, where S/N is the signal-to-noise ratio, but at the same time were firmly detected (>=12{sigma}) in the lower 17-60keV energy band. All registered sources are known X-ray emitters, which means that the catalogue has 100 percent purity in this respect. Additionally, 29 catalogued sources were detected significantly in different time slices of the survey. In the context of the survey, we present a hardness ratio for Galactic and extragalactic sources, an LMXB longitudinal asymmetry and a number-flux relation for non-blazar AGNs. At higher energies, in the 150-300keV energy band, 25 sources have been detected with S/N>=5{sigma}, including seven AGNs, 13 LMXBs, three HMXBs and two rotation-powered pulsars. Among LMXBs and HMXBs, we identified 12 black hole candidates (BHCs) and four neutron star (NS) binaries.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/504/681
- Title:
- Integrated BVJHKs for 650 open clusters
- Short Name:
- J/A+A/504/681
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We determine the integrated magnitudes and colours of 650 clusters in optical (BV) and the near-infrared (JHKs) passbands and construct the luminosity functions of the Galactic open clusters in these passbands.
- ID:
- ivo://CDS.VizieR/J/MNRAS/403/1491
- Title:
- Integrated magnitudes of synthetic star clusters
- Short Name:
- J/MNRAS/403/1491
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This paper presents integrated magnitudes and colours for synthetic clusters. The integrated parameters have been obtained for the whole cluster population as well as for the main-sequence (MS) population of star clusters. We have also estimated observed integrated magnitudes and colours of the MS population of galactic open clusters, Large Magellanic Cloud (LMC) and Small Magellanic Cloud (SMC) star clusters.
- ID:
- ivo://CDS.VizieR/J/A+AS/104/379
- Title:
- Integrated Photometry of open clusters
- Short Name:
- J/A+AS/104/379
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Galactic open clusters provide an abundant sample of stellar aggregates of various sizes, ages and metal abundances, apt to constitute a template for comparison with star systems in other galaxies. In this paper we present and discuss a standard methodology to synthesize U,B,V fluxes and colours, and apply it to a set of 138 open clusters. Results are compared with previous ones available in the literature. We were able to calibrate a mass-luminosity relation by which we evaluated the mass of ~ 400 open clusters, leading to a well defined present-day mass function. The number-complete sample of galactic open clusters presented in Battinelli & Capuzzo-Dolcetta (1992AJ....103.1596B) is enlarged of a 15%.
- ID:
- ivo://CDS.VizieR/J/AJ/149/32
- Title:
- Integrated radio continuum spectra of galaxies
- Short Name:
- J/AJ/149/32
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We investigate the spectral shape of the total continuum radiation, between 74MHz and 5GHz (400-6cm in wavelength), for a large sample of bright galaxies. We take advantage of the overlapping survey coverage of the VLA Low-Frequency Sky Survey, the Westerbork Northern Sky Survey, the NRAO VLA Sky Survey, and the Green Bank 6cm Survey to achieve significantly better resolution, sensitivity, and sample size compared to prior efforts of this nature. For our sample of 250 bright galaxies we measure a mean spectral index, {alpha}, of -0.69 between 1.4 and 4.85GHz, -0.55 between 325MHz and 1.4GHz, and -0.45 between 74 and 325MHz, which amounts to a detection of curvature in the mean spectrum. The magnitude of this curvature is approximately {Delta}{alpha}=-0.2 per logarithmic frequency decade when fit with a generalized function having constant curvature. No trend in low-frequency spectral flattening versus galaxy inclination is evident in our data, suggesting that free-free absorption is not a satisfying explanation for the observed curvature. The ratio of thermal to non-thermal emission is estimated through two independent methods: (1) using the IRAS far-IR fluxes and (2) with the value of the total spectral index. Method (1) results in a distribution of 1.4GHz thermal fractions of 9%+/-3%, which is consistent with previous studies, while method (2) produces a mean 1.4GHz thermal fraction of 51% with dispersion 26%. The highly implausible values produced by method (2) indicate that the sum of typical power-law thermal and non-thermal components is not a viable model for the total spectral index between 325 and 1.4GHz. An investigation into relationships between spectral index, infrared-derived quantities, and additional source properties reveals that galaxies with high radio luminosity in our sample are found to have, on average, a flatter radio spectral index, and early types tend to have excess radio emission when compared to the radio-infrared ratio of later types. Early types also have radio emission that is more compact than later type galaxies, as compared to the optical size of the galaxy. Despite these differences, no relation between spectral index and galaxy type is detected.
- ID:
- ivo://CDS.VizieR/J/AZh/83/542
- Title:
- Integrated Radio Luminosities of Pulsars
- Short Name:
- J/AZh/83/542
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The integrated radio luminosities of 311 long-period (P>0.1s) and 27 short-period (P<0.1s) pulsars have been calculated using a new compilation of radio spectra. The luminosities are in the range 10^27^-10^30^erg/s for 88% of the long-period pulsars and 10^28^-10^31^erg/s for 88% of the short-period pulsars. We find a high correlation between the luminosity L and the estimate L1=S_(400)_*d^2^ from the catalog of Taylor et al. (1993, See Cat. <VII/189>. The factor 'eta' for transformation of the rotational energy of the neutron star into radio emission increases/decreases with increasing period for long-period/short-period pulsars. The mean value of 'eta'=-3.73 for the long-period and -4.85 for the short-period pulsars.
- ID:
- ivo://CDS.VizieR/J/MNRAS/335/233
- Title:
- Integrated Spectra of Open Clusters
- Short Name:
- J/MNRAS/335/233
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a library of 39 open cluster optical/near-IR integrated spectra. The data were obtained at CASLEO (San Juan, Argentina) and LNA (Itajuba, Brazil). Eight additional spectra obtained at ESO (La Silla, Chile), also employed in the present analysis, are already available at CDS (see cat. <III/219>). The data were combined in order to derive high S/N templates of young and intermediate-age populations sampling their evolutionary states with unprecedented time resolution at nearly solar metallicity. These template spectra, also included in the library, are useful, e.g., for population synthesis techniques applied to galaxies and for estimates of individual cluster parameters in the Milky Way as well as in external galaxies.
- ID:
- ivo://CDS.VizieR/J/A+A/550/A114
- Title:
- Integrated spectroscopy of HRS galaxies
- Short Name:
- J/A+A/550/A114
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present long-slit integrated spectroscopy of 238 late-type galaxies belonging to the Herschel Reference Survey, a volume-limited sample representative of the nearby universe. This sample has a unique legacy value since it was ideally defined for any statistical study of the multifrequency properties of galaxies spanning a wide range in morphological type and luminosity. The spectroscopic observations cover the spectral range 3600-6900{AA} at a resolution R~=1000 and are thus suitable for separating both the underlying absorption from the emission of the H{beta} line and the two [NII] lines from the H{alpha} emission. We measured the fluxes and the equivalent widths of the strongest emission lines ([OII]{lambda}3727, H{beta}, [OIII]{lambda}4959 and [OIII]{lambda}5007, [NII]{lambda}6548, H{alpha}, [NII]{lambda}6584, [SII]{lambda}6717, and [SII]{lambda}6731). We used the data to study the distribution of the equivalent width of all the emission lines, of the Balmer decrement C(H{beta}), and of the observed underlying Balmer absorption under H{beta} (EWH{beta}_abs_) in this sample. Combining these new spectroscopic data with those available at other frequencies, we also study the dependence of C(H{beta}) and EWH{beta}_abs_ on morphological type, stellar mass, stellar surface density, star formation rate, birthrate parameter, and metallicity in galaxies belonging to different environments (fields vs. Virgo cluster). The distribution of the equivalent width of all the emission lines, of C(H{beta}) (or equivalently of A(H{alpha}), and of EWH{beta}_abs_ are systematically different in cluster and field galaxies. The Balmer decrement increases with the stellar mass, stellar surface density, metallicity, and star formation rate of the observed galaxies, while it is unexpectedly almost independent of the column density of the atomic and molecular gas. The dependence of C(H{beta}) on stellar mass is steeper than previously found in other works. The underlying Balmer absorption does not significantly change with any of these physical parameters.
- ID:
- ivo://CDS.VizieR/J/A+A/565/A49
- Title:
- Integrated spectroscopy of 6 LMC clusters
- Short Name:
- J/A+A/565/A49
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- To increase the number of studied star clusters (SCs) of the Large Magellanic Cloud (LMC), we present flux-calibrated integrated spectra in the optical range ({lambda}=3700-6800{AA}) for six poorly studied LMC SCs of IVA type. This type corresponds to the age range between 200 and 400Myr. We also aim at creating a new template spectrum representative of this age range at the metallicity level of the LMC. Foreground reddening E(B-V) values and ages are derived by applying the template matching method that consists of comparing the line strengths and continuum distribution of the cluster spectra with those of template cluster spectra with known properties. The equivalent width (EW) of the Balmer lines and the diagnostic diagrams involving the sum of EWs of selected spectral lines were also employed as age indicators. For the first time we provide estimates of the clusters' reddenings and ages. As expected, all the clusters appear to be of nearly the same age, their mean value being (400+/-100)Myr, while the resulting mean E(B-V) values range between 0.00 and 0.10mag. The present cluster sample complements previous ones in an effort to gather a spectral library with several clusters per age bin. By averaging the reddening-corrected integrated spectra, weighted by their signal-to-noise (S/N) ratios, a new high S/N ratio template spectrum of 400Myr has been created.
- ID:
- ivo://CDS.VizieR/J/ApJ/872/16
- Title:
- Integrated star formation law revisited. I.
- Short Name:
- J/ApJ/872/16
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We use new and updated gas- and dust-corrected star formation rate (SFR) surface densities to revisit the integrated star formation law for local "quiescent" spiral, dwarf, and low surface brightness galaxies. Using UV-based SFRs with individual IR-based dust corrections, we find that "normal" spiral galaxies alone define a tight Σ<SUB>(HI+H2)–Σ</SUB>SFR_ relation described by an n=1.41<SUB>–0.07</SUB><SUP>+0.07</SUP> power law with a dispersion of 0.28<SUB>–0.02</SUB><SUP>+0.02</SUP> (errors reflect fitting and statistical uncertainties). The SFR surface densities are only weakly correlated with HI surface densities alone, exhibiting a stronger and roughly linear correlation with H<SUB>2</SUB> surface densities, similar to what is seen in spatially resolved measurements of disks. However, many dwarf galaxies lie below the star formation law defined by spirals, suggesting a low-density threshold in the integrated star formation law. We consider alternative scaling laws that better describe both spirals and dwarfs. Our improved measurement precision also allows us to determine that much of the scatter in the star formation law is intrinsic, and we search for correlations between this intrinsic scatter and secondary physical parameters. We find that dwarf galaxies exhibit second-order correlations with the total gas fraction, stellar mass surface density, and dynamical time, which may explain much of the scatter in the star formation law. Finally, we discuss various systematic uncertainties that should be kept in mind when interpreting any study of the star formation law, particularly the X(CO) conversion factor and the diameter chosen to define the star-forming disk in a galaxy.