- ID:
- ivo://CDS.VizieR/J/ApJ/807/27
- Title:
- IN-SYNC. III. Radial velocities of IC348 stars
- Short Name:
- J/ApJ/807/27
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Most field stars will have encountered the highest stellar density and hence the largest number of interactions in their birth environment. Yet the stellar dynamics during this crucial phase are poorly understood. Here we analyze the radial velocities measured for 152 out of 380 observed stars in the 2-6Myr old star cluster IC 348 as part of the SDSS-III APOGEE. The radial velocity distribution of these stars is fitted with one or two Gaussians, convolved with the measurement uncertainties including binary orbital motions. Including a second Gaussian improves the fit; the high-velocity outliers that are best fit by this second component may either (1) be contaminants from the nearby Perseus OB2 association, (2) be a halo of ejected or dispersing stars from IC 348, or (3) reflect that IC 348 has not relaxed to a Gaussian velocity distribution. We measure a velocity dispersion for IC 348 of 0.72+/-0.07km/s (or 0.64+/-0.08km/s if two Gaussians are fitted), which implies a supervirial state, unless the gas contributes more to the gravitational potential than expected. No evidence is found for a dependence of this velocity dispersion on distance from the cluster center or stellar mass. We also find that stars with lower extinction (in the front of the cloud) tend to be redshifted compared with stars with somewhat higher extinction (toward the back of the cloud). This data suggest that the stars in IC 348 are converging along the line of sight. We show that this correlation between radial velocity and extinction is unlikely to be spuriously caused by the small cluster rotation of 0.024+/-0.013km/s/arcmin or by correlations between the radial velocities of neighboring stars. This signature, if confirmed, will be the first detection of line of sight convergence in a star cluster. Possible scenarios for reconciling this convergence with IC 348's observed supervirial state include: (a) the cluster is fluctuating around a new virial equilibrium after a recent disruption due to gas expulsion or a merger event, or (b) the population we identify as IC 348 results from the chance alignment of two sub-clusters converging along the line of sight. Additional measurements of tangential and radial velocities in IC 348 will be important for clarifying the dynamics of this region and informing models of the formation and evolution of star clusters.
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- ID:
- ivo://CDS.VizieR/J/ApJ/818/59
- Title:
- IN-SYNC. IV. YSOs in Orion A
- Short Name:
- J/ApJ/818/59
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of the Sloan Digital Sky Survey APOGEE INfrared Spectroscopy of Young Nebulous Clusters program (IN-SYNC) survey of the Orion A molecular cloud. This survey obtained high-resolution near-infrared spectroscopy of about 2700 young pre-main-sequence stars on a ~6{deg} field of view. We have measured accurate stellar parameters (T_eff_, logg, vsini) and extinctions and placed the sources in the Hertzsprung-Russel diagram (HRD). We have also extracted radial velocities for the kinematic characterization of the population. We compare our measurements with literature results to assess the performance and accuracy of the survey. Source extinction shows evidence for dust grains that are larger than those in the diffuse interstellar medium: we estimate an average R_V_=5.5 in the region. Importantly, we find a clear correlation between HRD inferred ages and spectroscopic surface-gravity-inferred ages and between extinction and disk presence; this strongly suggests a real spread of ages larger than a few Myr. Focusing on the young population around NGC 1980/{iota} Ori, which has previously been suggested to be a separate, foreground, older cluster, we confirm its older (~5Myr) age and low A_V_, but considering that its radial velocity distribution is indistinguishable from Orion A's population, we suggest that NGC 1980 is part of Orion A's star formation activity. Based on their stellar parameters and kinematic properties, we identify 383 new candidate members of Orion A, most of which are diskless sources in areas of the region poorly studied by previous works.
- ID:
- ivo://CDS.VizieR/J/ApJ/869/72
- Title:
- IN-SYNC. VIII. YSOs in NGC 1333, IC 348 and Orion A
- Short Name:
- J/ApJ/869/72
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this paper, we address two issues related to primordial disk evolution in three clusters (NGC1333, IC348, and OrionA) observed by the INfrared Spectra of Young Nebulous Clusters (IN-SYNC) project. First, in each cluster, averaged over the spread of age, we investigate how disk lifetime is dependent on stellar mass. The general relation in IC348 and OrionA is that primordial disks around intermediate-mass stars (2-5M_{sun}_) evolve faster than those around loss-mass stars (0.1-1M_{sun}_), which is consistent with previous results. However, considering only low-mass stars, we do not find a significant dependence of disk frequency on stellar mass. These results can help to better constrain theories on gas giant planet formation timescales. Second, in the OrionA molecular cloud, in the mass range of 0.35-0.7M_{sun}_, we provide the most robust evidence to date for disk evolution within a single cluster exhibiting modest age spread. By using surface gravity as an age indicator and employing 4.5{mu}m excess as a primordial disk diagnostic, we observe a trend of decreasing disk frequency for older stars. The detection of intra-cluster disk evolution in NGC1333 and IC348 is tentative, since the slight decrease of disk frequency for older stars is a less than 1{sigma} effect.
- ID:
- ivo://CDS.VizieR/J/A+A/475/775
- Title:
- INTEGRAL all-sky survey of hard X-ray sources
- Short Name:
- J/A+A/475/775
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present results of an all-sky hard X-ray survey based on almost four years of observations with the IBIS telescope onboard the INTEGRAL observatory. The dead time-corrected exposure of the survey is about 33Ms. Approximately 12% and 80% of the sky has been covered to limiting fluxes lower than 1 and 5mCrab, respectively. Our catalog of detected sources includes 403 objects, 316 of which exceed a 5{sigma} detection threshold on the time-averaged map of the sky, and the rest were detected in various subsamples of exposures.
- ID:
- ivo://CDS.VizieR/J/A+A/523/A61
- Title:
- INTEGRAL all-sky survey of hard X-ray sources
- Short Name:
- J/A+A/523/A61
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This paper is the second in a series devoted to the hard X-ray (17-60keV) whole sky survey performed by the INTEGRAL observatory over seven years. Here we present a catalog of detected sources that includes 521 objects, 449 of which exceed a 5{sigma} detection threshold on the time-averaged map of the sky, and 53 were detected in various subsamples of exposures. Among the identified sources with known and suspected nature, 262 are Galactic (101 low-mass X-ray binaries, 94 high-mass X-ray binaries, 37 cataclysmic variables, and 30 of other types) and 221 are extragalactic, including 217 active galactic nuclei (AGNs) and 4 galaxy clusters. The extragalactic (|b|>5deg) and Galactic (|b|<5deg) persistently detected source samples have high identification completeness (respectively ~96% and ~93%) and are valuable for population studies.
- ID:
- ivo://nasa.heasarc/intbsc
- Title:
- INTEGRAL Bright Source Catalog
- Short Name:
- INTEGRAL/BSC
- Date:
- 27 Sep 2024
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The INTEGRAL Bright Source Catalog is based on publicly available data from the two main instruments (IBIS and SPI) on board INTEGRAL (see Winkler et al. 2003, A&A, 411, L1 for a description of the INTEGRAL spacecraft and instrument packages). INTEGRAL began collecting data in October 2002. This catalog will be regularly updated as data become public (~14 months after they are obtained). The Bright Source Catalog is a collaborative effort between the INTEGRAL Science Data Center (ISDC) in Switzerland and the NASA Goddard Space Flight Center (GSFC) INTEGRAL Guest Observer Facility (GOF). The results presented here are a result of a semi-automated analysis and they should be considered as approximate: they are intended to serve as a guideline to those interested in pursuing more detailed follow-up analyses. The data from the imager ISGRI (Lebrun et al. 2003, A&A, 411, L141) have been analyzed at the INTEGRAL Science Data Centre (ISDC), while the SPI (Vedrenne et al. 2003, A&A, 411, L63) data analysis was performed at GSFC as a service of the INTEGRAL GOF. This database table was first created in September 2004. It is based on the online web page maintained by the INTEGRAL GOF at the URL <a href="http://heasarc.gsfc.nasa.gov/docs/integral/INTEGRAL_bright_sources.html">http://heasarc.gsfc.nasa.gov/docs/integral/INTEGRAL_bright_sources.html</a> and is updated on a weekly basis whenever the web page is updated. This is a service provided by NASA HEASARC .
- ID:
- ivo://CDS.VizieR/J/A+A/576/A58
- Title:
- Integral Field 560-680nm observation of M81
- Short Name:
- J/A+A/576/A58
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- M81 has the nearest active nucleus with broad H{alpha} emission. A detailed study of this galaxy's centre is important for understanding the innermost structure of the AGN phenomenon. Our goal is to seek previously undetected structures using additional techniques to reanalyse a data cube obtained with the GMOS-IFU installed on the Gemini North telescope (Schnorr Muller et al., 2011MNRAS.413..149S). We analysed the data cube using techniques of noise reduction, spatial deconvolution, starlight subtraction, PCA Tomography and comparison with HST images. We identified a hot bubble with T>43500K that is associated with strong emission of [NII]{lambda}5755{AA} and large [OI]{lambda}6300/H{alpha} ratio, as well as with a bluish continuum, surrounded by a thin shell of H{alpha}+[NII] emission. We also reinterpret the outflow found by Schnorr Muller et al. (2011MNRAS.413..149S) showing that the blueshifted cone nearly coincides with the radio jet, as expected. We interpret the hot bubble as likely to be caused by post starburst events that left one or more clusters of young stars, somewhat similar to the ones found at the centre of the Milky Way, like the Arches and the IRS 16 clusters. Shocked structures from combined young stellar winds or supernova remnants are probably the cause of this hot gas and the low ionization emission.
- ID:
- ivo://CDS.VizieR/J/A+A/577/A21
- Title:
- Integral Field Spectroscopy of 8 BCGs
- Short Name:
- J/A+A/577/A21
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Blue Compact Galaxies (BCG) are gas rich, low luminosity, low metallicity systems, undergoing a violent burst of star formation. These galaxies offer us a unique opportunity to investigate collective star formation and its effects on galaxy evolution in a relatively simple environment. Spatially resolved spectrophotometric studies of BCGs are essential for a better understanding of the role of starburst-driven feedback processes on the kinematical and chemical evolution of low-mass galaxies near and far. We carry out an integral field spectroscopic study of a sample of BCGs, with the aim to probe the morphology, kinematics, dust extinction, and excitation mechanisms of their warm interstellar medium. Eight BCGs were observed with the VIMOS integral field unit at the Very Large Telescope using blue and orange grisms in high resolution mode. At a spatial sampling of 0.67 per spaxel we covered about 30x30-arcsec on the sky, with a wavelength range of 4150...7400{AA}. Emission lines were fitted with a single Gaussian profiles to measure their wavelength, flux, and width. From these data we built two-dimensional maps of the continuum and the most prominent emission-lines, as well as diagnostic line ratios, extinction, and kinematic maps. An atlas of emission-line fluxes and continuum emission; ionization, interstellar extinction, and electron density maps from line ratios; velocity and velocity dispersion fields. Additionally, from integrated spectroscopy, tables of the extinction corrected line fluxes and equivalent widths, diagnostic-line ratios, physical parameters and abundances for the brightest star-forming knots and for the whole galaxy.
- ID:
- ivo://nasa.heasarc/intibisagn
- Title:
- INTEGRAL IBIS AGN Catalog
- Short Name:
- INTIBISAGN
- Date:
- 27 Sep 2024
- Publisher:
- NASA/GSFC HEASARC
- Description:
- In this work, the authors present the most comprehensive INTEGRAL active galactic nucleus (AGN) sample. It lists 272 AGN for which they have secure optical identifications, precise optical spectroscopy and measured redshift values plus X-ray spectral information, i.e. 2-10 and 20-100 keV fluxes plus column densities. In their paper, the authors mainly use this sample to study the absorption properties of active galaxies, to probe new AGN classes and to test the AGN unification scheme. The authors find that half (48%) of the sample is absorbed, while the fraction of Compton-thick AGN is small (~7%). In line with their previous analysis, they have however shown that when the bias towards heavily absorbed objects which are lost if weak and at large distance is removed, as is possible in the local Universe, the above fractions increase to become 80% and 17%, respectively. The authors also find that absorption is a function of source luminosity, which implies some evolution in the obscuration properties of AGN. A few peculiar classes, so far poorly studied in the hard X-ray band, have been detected and studied for the first time such as 5 X-ray bright optically normal galaxies (XBONGs), 5 type 2 QSOs and 11 low-ionization nuclear emission regions. In terms of optical classification, this sample contains 57% type 1 and 43% type 2 AGN; this subdivision is similar to that found in X-rays if unabsorbed versus absorbed objects are considered, suggesting that the match between optical and X-ray classifications is on the whole good. Only a small percentage of sources (12%) does not fulfill the expectation of the unified theory as the authors find 22 type 1 AGN which are absorbed and 10 type 2 AGN which are unabsorbed. Studying in depth these outliers they found that most of the absorbed type 1 AGN have X-ray spectra characterized by either complex or warm/ionized absorption more likely due to ionized gas located in an accretion disc wind or in the bi-conical structure associated with the central nucleus, therefore unrelated to the toroidal structure. Among the 10 type 2 AGN which are unabsorbed, at most 3-4% are still eligible to be classified as 'true' type 2 AGN. In the fourth INTEGRAL/IBIS survey (Bird et al. 2010, ApJS, 186, 1, available in the HEASARC database as the IBISCAT4 table), there are 234 objects which have been identified with AGN. To this set of sources, the present authors then added 38 galaxies listed in the INTEGRAL all-sky survey by Krivonos et al. (2007, A&A, 475, 775, available in the HEASARC database as the INTIBISASS table) updated on the website (<a href="http://hea.iki.rssi.ru/integral/survey/catalog.php">http://hea.iki.rssi.ru/integral/survey/catalog.php</a>) but not included in the Bird et al. catalog due to the different sky coverage (these latter sources are indicated with hard_flag = 'h' values in this HEASARC table). The final data set presented and discussed in the reference paper and constituting this table therefore comprises 272 AGN and was last updated in March 2011 March. It represents the most complete view of the INTEGRAL extragalactic sky as of the date of publication in 2012. This table was created by the HEASARC in October 2014 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/MNRAS/426/1750">CDS Catalog J/MNRAS/426/1750</a> files tablea1.dat and refs.dat. This is a service provided by NASA HEASARC .
- ID:
- ivo://CDS.VizieR/J/MNRAS/426/1750
- Title:
- INTEGRAL/IBIS AGN catalogue
- Short Name:
- J/MNRAS/426/1750
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this work we present the most comprehensive INTEGRAL active galactic nucleus (AGN) sample. It lists 272 AGN for which we have secure optical identifications, precise optical spectroscopy and measured redshift values plus X-ray spectral information, i.e. 2-10 and 20-100keV fluxes plus column density. Here we mainly use this sample to study the absorption properties of active galaxies, to probe new AGN classes and to test the AGN unification scheme.