A5002340875- Astrophysics and Cosmic Phenomena
- Astronomy and Astrophysical Research
- Astronomical Observations and Instrumentation
- Galaxies: Formation, Evolution, Phenomena
- Radio Astronomy Observations and Technology
- Dark Matter and Cosmic Phenomena
- Gamma-ray bursts and supernovae
- Stellar, planetary, and galactic studies
- Calibration and Measurement Techniques
- Neutrino Physics Research
- Remote Sensing in Agriculture
- Astrophysical Phenomena and Observations
- Particle Detector Development and Performance
- Adaptive optics and wavefront sensing
- Particle Accelerators and Free-Electron Lasers
- Advanced Computational Techniques and Applications
- History and Developments in Astronomy
- Time Series Analysis and Forecasting
- Research Data Management Practices
- Scientific Research and Discoveries
- Scientific Measurement and Uncertainty Evaluation
- Astrophysics and Star Formation Studies
- Gyrotron and Vacuum Electronics Research
- Pulsars and Gravitational Waves Research
- Computational Physics and Python Applications
Center for Astrophysics Harvard & Smithsonian
2015-2024
Smithsonian Astrophysical Observatory
2011-2020
CFA Institute
2020
Harvard University Press
2020
Max Planck Institute for Astronomy
2018
Max Planck Society
2018
University of Naples Federico II
2007-2017
European Southern Observatory
2016
Community Farm Alliance
2015
National Institute for Astrophysics
2013
The third catalog of active galactic nuclei (AGNs) detected by the Fermi-LAT (3LAC) is presented. It based on (3FGL) sources between 100 MeV and 300 GeV with a Test Statistic (TS) greater than 25, 2008 August 4 2012 July 31. 3LAC includes 1591 AGNs located at high Galactic latitudes (|b|>10{\deg}), 71% increase over second 2 years data. There are 28 duplicate associations, thus 1563 2192 high-latitude gamma-ray 3FGL AGNs. Most them (98%) blazars. About half newly blazars unknown type, i.e.,...
ABSTRACT We have started a new, deep multi-imaging survey of the Fornax cluster, dubbed Deep Survey (FDS), at VLT Telescope (VST). In this paper we present photometry inside two square degrees around bright galaxy NGC 1399 in core cluster. found that cluster is characterized by very extended and diffuse envelope surrounding luminous 1399: map surface brightness out to 33 arcmin (∼192 kpc) from center down μ g ∼ 31 mag arcsec −2 band. The allows us detect faint stellar bridge intracluster...
We present a catalog of radio-loud candidate gamma-ray emitting blazars with WISE mid-infrared colors similar to the confirmed blazars. The is assembled from sources detected in all four filters, compatible three-dimensional locus blazars, and which can be spatially cross-matched radio either one three surveys: NVSS, FIRST and/or SUMSS. Our initial selection uses slightly modified version previously successful algorithms. then select only using measure radio-to-IR flux, q22 parameter,...
Despite the large number of discoveries made recently by Fermi, origins so called unidentified gamma-ray sources remain unknown. The these suggests that among them there could be a population significantly contributes to isotropic background and is therefore crucial understand their nature. first step toward complete comprehension source identify those can associated with blazars, most numerous class extragalactic in sky. Recently, we discovered blazars recognized separated from other using...
Blazars constitute the most interesting and enigmatic class of extragalactic gamma-ray sources dominated by non-thermal emission. In this Letter, we show how WISE infrared data make possible to identify a distinct region [3.4]-[4.6]-[12] micron color-color diagram where thermal radiation are separated from those emission, in particular blazar population. This delineated as Blazar Strip (WBS), it is powerful new diagnostic tool when full survey released. The WBS can be used extract...
Blazars constitute the most enigmatic class of extragalactic gamma-ray sources, and their observational features have been ascribed to a relativistic jet closely aligned line sight. They are generally divided in two main classes: BL Lac objects (BL Lacs) Flat Spectrum Radio Quasars (FSRQs). In case Lacs double bumped spectral energy distribution (SED) is described by Synchrotron Self Compton (SSC) emission, while for FSRQs it interpreted as due External (EC) emission. Recently, we showed...
The Fornax Deep Survey (FDS), an imaging survey in the u', g', r', and i'-bands, has a supreme resolution image depth compared to previous spatially complete Cluster Catalog (FCC). Our new data allows us study galaxies down r'-band magnitude m$_{r'}\approx$21 mag (M$_{r'}\approx$-10.5 mag). These provide important legacy dataset cluster. We aim present (FDS) dwarf galaxy catalog, focusing on explaining reduction calibrations, assessing quality of data, describing methods used for defining...
Abstract As part of the Fornax Deep Survey with ESO VLT Telescope, we present new g - and r -band mosaics SW group Cluster. It covers an area 3 × 2 square degrees around central galaxy NGC 1316. The deep photometry, high spatial resolution OmegaCam, large covered allow us to study structure, trace stellar halo formation, look at environment. We map surface brightness profile out 33′ (∼200 kpc ∼ 15 R e ) from center, down <?CDATA ${\mu }_{g}\sim 31\,\mathrm{mag}$?> arcsec −2 }_{r}\sim...
MLPQNA stands for Multi Layer Perceptron with Quasi Newton Algorithm and it is a machine learning method which can be used to cope regression classification problems on complex massive data sets. In this paper we give the formal description of present results its application evaluation photometric redshifts quasars. The set experiment was obtained by merging four different surveys (SDSS, GALEX, UKIDSS WISE), thus covering wide range wavelengths from UV mid-infrared. able i) achieve very high...
We report the discovery of a complex extended density enhancement in Globular Clusters (GCs) central $\sim 0.5(^{\circ})^2$ ($\sim 0.06$ Mpc$^2$) Fornax cluster, corresponding to 50\%$ area within 1 core radius. This overdensity connects GC system NGC1399 most those neighboring galaxies 0.6^{\circ}$ 210$ kpc) along W-E direction. The asymmetric structure suggests that cluster experienced lively history interactions have left clear imprint on spatial distribution GCs. dominant is more...
Abstract In the core of Fornax cluster, on west side NGC 1399, we have detected a previously unknown region intracluster light (ICL). It is made up by several faint ( <?CDATA ${\mu }_{r}\simeq 28\mbox{--}29$?> mag arcsec −2 ) patches diffuse light. The bulk ICL located in between three bright galaxies core, 1387, 1379, and 1381, at $10\leqslant R\leqslant 40$?> arcmin (∼58–230 kpc) from central galaxy 1399. We show that counterpart known over-density population blue globular clusters (GCs)....
We present two catalogs of radio-loud candidate blazars whose WISE mid-infrared colors are selected to be consistent with the confirmed gamma-ray emitting blazars. The first catalog is improved and expanded release WIBRaLS presented by D'Abrusco et al. (2014): it includes sources detected in all four filters, spatially cross-matched radio source one three surveys based on their q22 spectral parameter. WIBRaLS2 9541 classified as BL Lacs, FSRQs or mixed candidates colors. second catalog,...
Blazars, one of the most extreme class active galaxies, constitute so far largest known population $\gamma$-ray sources and their number is continuously growing in Fermi catalogs. However latest release catalog there still a large fraction that are classified as blazar candidate uncertain type (BCUs) for which optical spectroscopic observations necessary to confirm nature associations. In addition about 1/3 point listed Third Fermi-LAT Source Catalog (3FGL) unassociated lacking an assigned...
Context . Dwarf galaxies are the most common type of in galaxy clusters. Due to their low mass, they more vulnerable environmental effects than massive galaxies, and thus optimal for studying environment on evolution. By comparing properties dwarf with different masses, morphological types, cluster-centric distances we can obtain information about physical processes clusters that play a role evolution these objects shape properties. The Fornax Deep Survey Catalog (FDSDC) includes 564 cluster...
Abstract The Chandra Source Catalog (CSC) is a virtual X-ray astrophysics facility that enables both detailed individual source studies and statistical of large samples sources detected in Advanced CCD Imaging Spectrometer High Resolution Camera-I imaging observations obtained by the Observatory. catalog provides carefully curated, high-quality, uniformly calibrated analyzed tabulated positional, spatial, photometric, spectral, temporal properties, as well science-ready data products. latter...
The combination between non-thermal and thermal emission in γ-ray blazars pushes them to a specific region of the mid-infrared three-dimensional color diagram, so-called blazar locus, built based on observations performed with Wide-field Infrared Survey Explorer. selection candidates these colors has been extensively used past decade hunt for counterparts unassociated sources observed Fermi Large Area Telescope search new optical spectroscopic campaigns. In this work, we provide theoretical...
We present a new method for identifying blazar candidates by examining the locus, i.e. region occupied Fermi gamma-ray blazars in three-dimensional color space defined WISE infrared colors. This is refinement of our previous approach that made use two-dimensional projection distribution emitting (the Strip) three color-color planes (Massaro et al. 2012a). In this paper, we define locus means Principal Component (PCs) analysis colors large sample composed all ROMA-BZCAT sources with...
About one third of the gamma-ray sources listed in second Fermi LAT catalog (2FGL) have no firmly established counterpart at lower energies so being classified as unidentified (UGSs). Here we propose a new approach to find candidate counterparts for UGSs based on 325 MHz radio survey performed with Westerbork Synthesis Radio Telescope (WSRT) northern hemisphere. First investigate low-frequency properties blazars, largest known population sources; then search similar combining information...
A significant fraction ($\sim 30$ %) of the gamma-ray sources listed in second $\textit{Fermi}$ LAT (2FGL) catalog is still unknown origin, being not yet associated with counterparts at lower energies. Using available information energies and optical spectroscopy on selected these objects we can pinpoint their exact nature. Here present a pilot project pointing to assess effectiveness several classification methods developed select blazar candidates. To this end, report spectroscopic...
We present an analysis of the optical spectra available in Sloan Digital Sky Survey data release nine (SDSS DR9) for blazars listed ROMA-BZCAT and γ-ray blazar candidates selected according to their IR colors. First, we adopt a statistical approach based on Monte Carlo simulations find counterparts catalog. Then, crossmatched SDSS spectroscopic catalog with our samples candidates, searching those classify blazar-like sources and, whenever possible, confirm redshifts. Our main objectives are...
One of the main scientific objectives ongoing Fermi mission is unveiling nature unidentified gamma-ray sources (UGSs). Despite large improvements in localization with respect to past missions, about one third Fermi-detected objects are still not associated low energy counterparts. Recently, using Wide-Field Infrared Survey Explorer (WISE) survey, we discovered that blazars, rarest class Active Galactic Nuclei and largest population sources, can be recognized separated from other...
The extragalactic $\gamma$-ray sky is dominated by emission from blazars, a peculiar class of active galactic nuclei (AGNs). Many the sources included in Fermi -Large Area Telescope Third Source catalog (3FGL) are classified as blazar candidate uncertain type (BCU) because there no optical spectra available literature to confirm their nature. In 2013 we started spectroscopic campaign look for counterparts BCUs and Unidentified Sources. main goal our investigation nature these having...
A significant fraction (~30%) of the high-energy gamma-ray sources listed in second Fermi LAT catalog (2FGL) are still unknown origin, being not yet associated with counterparts at low energies. We recently developed a new association method to identify if there is blazar candidate within positional uncertainty region generic 2FGL source. This entirely based on discovery that blazars have distinct infrared colors respect other extragalactic found thanks, Wide-field Infrared Survey Explorer...
This paper is based on the multi-band (ugri) Fornax Deep Survey (FDS) with VLT Telescope (VST). We study bright early-type galaxies (m_B<15 mag) in 9 square degrees around core of cluster, which covers virial radius. The main goal present work to provide analysis light distribution for all out unprecedented limits (in radius and surface brightness) release products resulting from this FDS bands. From isophote fit, we derive azimuthally averaged brightness profiles, position angle ellipticity...