Author
Juan Pablo Torres-Papaqui
Bio: Juan Pablo Torres-Papaqui is an academic researcher from Universidad de Guanajuato. The author has contributed to research in topics: Galaxy & Star formation. The author has an hindex of 13, co-authored 47 publications receiving 626 citations.
Topics: Galaxy, Star formation, Radio galaxy, Bulge, Elliptical galaxy
Papers
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National Autonomous University of Mexico1, Spanish National Research Council2, INAF3, Leibniz Institute for Astrophysics Potsdam4, European Southern Observatory5, University of Chile6, University of La Laguna7, University of Vienna8, Universidade Federal de Santa Catarina9, Autonomous University of Madrid10, Johns Hopkins University11, University of Sydney12, Universidade Federal de Itajubá13, Heidelberg University14, Ruhr University Bochum15, University of Granada16, University of St Andrews17, Complutense University of Madrid18, Royal Military College of Canada19, University of Cambridge20, Paris Diderot University21, Federal University of Rio de Janeiro22, Universidad de Guanajuato23, National Institute of Astrophysics, Optics and Electronics24, Pontifical Catholic University of Chile25, Max Planck Society26
TL;DR: The second public data release (DR2) of the Calar Alto Legacy Integral Field Area (CALIFA) survey as discussed by the authors contains over 1.5 million spectra.
Abstract: This paper describes the Second Public Data Release (DR2) of the Calar Alto Legacy Integral Field Area (CALIFA) survey. The data for 200 objects are made public, including the 100 galaxies of the First Public Data Release (DR1). Data were obtained with the integral-field spectrograph PMAS /PPak mounted on the 3.5 m telescope at the Calar Alto observatory. Two different spectral setups are available for each galaxy, (i) a low-resolution V500 setup covering the wavelength range 3745-7500 A with a spectral resolution of 6.0 A (FWHM); and (ii) a medium-resolution V1200 setup covering the wavelength range 3650-4840 A with a spectral resolution of 2.3 A (FWHM). The sample covers a redshift range between 0.005 and 0.03, with a wide range of properties in the color-magnitude diagram, stellar mass, ionization conditions, and morphological types. All the cubes in the data release were reduced with the latest pipeline, which includes improved spectrophotometric calibration, spatial registration, and spatial resolution. The spectrophotometric calibration is better than 6% and the median spatial resolution is 2´´ 4. In total, the second data release contains over 1.5 million spectra.
218 citations
01 Jan 2016
TL;DR: In this article, a computer algorithm was designed to identify contiguous emission regions, large and elongated enough to serve as GRG candidates, and applied it to the entire 1.4GHz NRAO VLA Sky survey (NVSS) image atlas.
Abstract: We present results of a search for giant radio galaxies (GRGs) larger than 1 Mpc in projected size. We designed a computer algorithm to identify contiguous emission regions, large and elongated enough to serve as GRG candidates, and applied it to the entire 1.4-GHz NRAO VLA Sky survey (NVSS) image atlas. Subsequent visual inspection of 1,000 such regions revealed 15 new GRGs, as well as many other candidate GRGs, some of them previously reported, for which no redshift was known. Our optical spectroscopy of 25 host galaxies with two 2.1-m telescopes in Mexico, and four others with the 10.4-m Gran Telescopio Canarias (GTC), yielded another 24 GRGs. We also obtained higher-resolution radio images with the Karl G. Jansky Very Large Array for some unconfirmed GRG candidates.
62 citations
TL;DR: In this paper, it was shown that the largest core of the Abell 85 galaxy displays the largest cusp radius, r = 4.57 ± 0.06 kpc (4.26± 0.
Abstract: We have found that the brightest cluster galaxy (BCG) in Abell 85, Holm 15A, displays the largest core so far known. Its cusp radius, r = 4.57 ± 0.06 kpc (4. ′′ 26±0.
56 citations
TL;DR: Holm 15A as discussed by the authors is the largest-cored BCG with a cusp radius of 4.26 × 4.57 × 0.06 kpc, which is more than 18 times larger than the mean for BCGs, and approximately 1/1/kpc larger than A2261-BCG.
Abstract: We have found that the brightest cluster galaxy (BCG) in Abell~85, Holm 15A, displays the largest core so far known. Its cusp radius, $r_{\gamma} = 4.57 \pm 0.06$ kpc ($4.26^{\prime\prime}\pm 0.06^{\prime\prime}$), is more than 18 times larger than the mean for BCGs, and $\geq1$ kpc larger than A2261-BCG, hitherto the largest-cored BCG (Postman, Lauer, Donahue, et al. 2012) Holm 15A hosts the luminous amorphous radio source 0039-095B and has the optical signature of a LINER. Scaling laws indicate that this core could host a supermassive black hole (SMBH) of mass $M_{\bullet}\thicksim (10^{9}-10^{11})\,M_{\odot}$. We suggest that cores this large represent a relatively short phase in the evolution of BCGs, whereas the masses of their associated SBMH might be set by initial conditions.
48 citations
TL;DR: In this paper, the authors presented results of a search for giant radio galaxies (GRGs) with a projected largest linear size in excess of 1 Mpc, and designed a computational algorithm to identify contiguous emission regions, large and elongated enough to serve as GRG candidates.
Abstract: We present results of a search for giant radio galaxies (GRGs) with a projected largest linear size in excess of 1 Mpc. We designed a computational algorithm to identify contiguous emission regions, large and elongated enough to serve as GRG candidates, and applied it to the entire 1.4-GHz NRAO VLA Sky survey (NVSS). In a subsequent visual inspection of 1000 such regions we discovered 15 new GRGs, as well as many other candidate GRGs, some of them previously reported, for which no redshift was known. Our follow-up spectroscopy of 25 of the brighter hosts using two 2.1-m telescopes in Mexico, and four fainter hosts with the 10.4-m Gran Telescopio Canarias (GTC), yielded another 24 GRGs. We also obtained higher-resolution radio images with the Karl G. Jansky Very Large Array for GRG candidates with inconclusive radio structures in NVSS.
42 citations
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01 Jan 1965
TL;DR: In this article, Maarten Schmidt solved the puzzle by recognizing the Balmer lines of hydrogen, strongly redshifted, in the spectrum of the quasar 3C 273, and reached the "most direct and least objectionable" conclusion, that 3c 273 was no star, but the enormously bright nucleus of a distant galaxy.
Abstract: In the early 1960s, astronomers were puzzled by quasars — sources of intense radio emission that seemed to be stars, but had unintelligible optical spectra. In 1963, Maarten Schmidt solved the puzzle by recognizing the Balmer lines of hydrogen, strongly redshifted, in the spectrum of the quasar 3C 273. Schmidt reached the "most direct and least objectionable" conclusion, that 3C 273 was no star, but the enormously bright nucleus of a distant galaxy.
505 citations
Space Telescope Science Institute1, Johns Hopkins University2, University of Kentucky3, University of Pittsburgh4, University of Wisconsin-Madison5, New Mexico State University6, Carnegie Institution for Science7, University of Chile8, New York University9, University of Utah10, Institute for the Physics and Mathematics of the Universe11, Nanjing University12, University of Texas at Austin13, Max Planck Society14, University of Iowa15, University of Washington16, National Autonomous University of Mexico17, Lawrence Berkeley National Laboratory18, Open University19, University of St Andrews20
TL;DR: In this paper, the authors describe the MaNGA Data Reduction Pipeline algorithms and centralized metadata framework that produce sky-subtracted spectrophotometrically calibrated spectra and rectified three-dimensional data cubes that combine individual dithered observations.
Abstract: Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) is an optical fiber-bundle integral-field unit (IFU) spectroscopic survey that is one of three core programs in the fourth-generation Sloan Digital Sky Survey (SDSS-IV). With a spectral coverage of 3622–10354 A and an average footprint of ~500 arcsec2 per IFU the scientific data products derived from MaNGA will permit exploration of the internal structure of a statistically large sample of 10,000 low-redshift galaxies in unprecedented detail. Comprising 174 individually pluggable science and calibration IFUs with a near-constant data stream, MaNGA is expected to obtain ~100 million raw-frame spectra and ~10 million reduced galaxy spectra over the six-year lifetime of the survey. In this contribution, we describe the MaNGA Data Reduction Pipeline algorithms and centralized metadata framework that produce sky-subtracted spectrophotometrically calibrated spectra and rectified three-dimensional data cubes that combine individual dithered observations. For the 1390 galaxy data cubes released in Summer 2016 as part of SDSS-IV Data Release 13, we demonstrate that the MaNGA data have nearly Poisson-limited sky subtraction shortward of ~8500 A and reach a typical 10σ limiting continuum surface brightness μ = 23.5 AB arcsec-2 in a five-arcsecond-diameter aperture in the g-band. The wavelength calibration of the MaNGA data is accurate to 5 km s-1 rms, with a median spatial resolution of 2.54 arcsec FWHM (1.8 kpc at the median redshift of 0.037) and a median spectral resolution of σ = 72 km s-1.
326 citations
University of Cambridge1, École normale supérieure de Lyon2, European Southern Observatory3, University of Wisconsin-Madison4, University of Kentucky5, Sternberg Astronomical Institute6, New Mexico State University7, University of Antofagasta8, University of Utah9, Institute for the Physics and Mathematics of the Universe10, University of Texas at Austin11, Johns Hopkins University12, Space Telescope Science Institute13, University of La Serena14, University of St Andrews15
TL;DR: In this paper, the authors studied the spatially resolved excitation properties of the ionised gas in a sample of 646 galaxies using integral field spectroscopy data from SDSS-IV MaNGA.
Abstract: We study the spatially resolved excitation properties of the ionised gas in a sample of 646 galaxies using integral field spectroscopy data from SDSS-IV MaNGA. Making use of Baldwin-Philips-Terlevich diagnostic diagrams we demonstrate the ubiquitous presence of extended (kpc scale) low ionisation emission-line regions (LIERs) in both star forming and quiescent galaxies. In star forming galaxies LIER emission can be associated with diffuse ionised gas, most evident as extra-planar emission in edge-on systems. In addition, we identify two main classes of galaxies displaying LIER emission: `central LIER' (cLIER) galaxies, where central LIER emission is spatially extended, but accompanied by star formation at larger galactocentric distances, and `extended LIER' (eLIER) galaxies, where LIER emission is extended throughout the whole galaxy. In eLIER and cLIER galaxies, LIER emission is associated with radially flat, low H$\alpha$ equivalent width of line emission ($
302 citations
National Radio Astronomy Observatory1, University of Manitoba2, Cornell University3, United States Naval Research Laboratory4, Space Telescope Science Institute5, University of Toronto6, Saint Anselm College7, California Institute of Technology8, University of California, Berkeley9, Max Planck Society10, Drexel University11, University of Alberta12, University of Minnesota13, University of the Western Cape14, University of Cape Town15, Universidad de Guanajuato16, Harvard University17, University of Bristol18, Academia Sinica Institute of Astronomy and Astrophysics19, Pennsylvania State University20, University of Iowa21, West Virginia University22, University of Colorado Boulder23, Newcastle University24, Leiden University25, Hebrew University of Jerusalem26, University of Washington27, University of Oxford28, Smithsonian Institution29, University of Illinois at Urbana–Champaign30, National Autonomous University of Mexico31, Spanish National Research Council32, European Southern Observatory33, University of Hamburg34, INAF35
TL;DR: The Very Large Array Sky Survey (VLASS) as discussed by the authors is a synoptic, all-sky radio sky survey with a unique combination of high angular resolution (≈2.5"), sensitivity (a 1σ goal of 70 μJy/beam in the coadded data), full linear Stokes polarimetry, time domain coverage, and wide bandwidth (2-4 GHz).
Abstract: The Very Large Array Sky Survey (VLASS) is a synoptic, all-sky radio sky survey with a unique combination of high angular resolution (≈2.5\"), sensitivity (a 1σ goal of 70 μJy/beam in the coadded data), full linear Stokes polarimetry, time domain coverage, and wide bandwidth (2-4 GHz). The first observations began in September 2017, and observing for the survey will finish in 2024. VLASS will use approximately 5500 hours of time on the Karl G. Jansky Very Large Array (VLA) to cover the whole sky visible to the VLA (Declination > −40∘), a total of 33,885 deg^2. The data will be taken in three epochs to allow the discovery of variable and transient radio sources. The survey is designed to engage radio astronomy experts, multi-wavelength astronomers, and citizen scientists alike. By utilizing an \"on the fly\" interferometry mode, the observing overheads are much reduced compared to a conventional pointed survey. In this paper, we present the science case and observational strategy for the survey, and also results from early survey observations.
288 citations
TL;DR: In this article, the optical variability of the Catalina Real-Time Transient Survey (CRTS) data was used to identify binary supermassive black hole (SMBH) binaries.
Abstract: Hierarchical assembly models predict a population of supermassive black hole (SMBH) binaries. These are not resolvable by direct imaging but may be detectable via periodic variability (or nanohertz frequency gravitational waves). Following our detection of a 5.2-year periodic signal in the quasar PG 1302−102, we present a novel analysis of the optical variability of 243 500 known spectroscopically confirmed quasars using data from the Catalina Real-time Transient Survey (CRTS) to look for close (<0.1 pc) SMBH systems. Looking for a strong Keplerian periodic signal with at least 1.5 cycles over a baseline of nine years, we find a sample of 111 candidate objects. This is in conservative agreement with theoretical predictions from models of binary SMBH populations. Simulated data sets, assuming stochastic variability, also produce no equivalent candidates implying a low likelihood of spurious detections. The periodicity seen is likely attributable to either jet precession, warped accretion discs or periodic accretion associated with a close SMBH binary system. We also consider how other SMBH binary candidates in the literature appear in CRTS data and show that none of these are equivalent to the identified objects. Finally, the distribution of objects found is consistent with that expected from a gravitational-wave-driven population. This implies that circumbinary gas is present at small orbital radii and is being perturbed by the black holes. None of the sources is expected to merge within at least the next century. This study opens a new unique window to study a population of close SMBH binaries that must exist according to our current understanding of galaxy and SMBH evolution.
263 citations