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16 results on '"José Sánchez-Gallego"'

1. Spectacular Nucleosynthesis from Early Massive Stars

Author

Alexander P. Ji, Sanjana Curtis, Nicholas Storm, Vedant Chandra, Kevin C. Schlaufman, Keivan G. Stassun, Alexander Heger, Marco Pignatari, Adrian M. Price-Whelan, Maria Bergemann, Guy S. Stringfellow, Carla Fröhlich, Henrique Reggiani, Erika M. Holmbeck, Jamie Tayar, Shivani P. Shah, Emily J. Griffith, Chervin F. P. Laporte, Andrew R. Casey, Keith Hawkins, Danny Horta, William Cerny, Pierre Thibodeaux, Sam A. Usman, João A. S. Amarante, Rachael L. Beaton, Phillip A. Cargile, Cristina Chiappini, Charlie Conroy, Jennifer A. Johnson, Juna A. Kollmeier, Haining Li, Sarah Loebman, Georges Meynet, Dmitry Bizyaev, Joel R. Brownstein, Pramod Gupta, Sean Morrison, Kaike Pan, Solange V. Ramirez, Hans-Walter Rix, and José Sánchez-Gallego

Subjects
Core-collapse supernovae, Nucleosynthesis, Nuclear astrophysics, Population II stars, Population III stars, Galactic archaeology, Astrophysics, QB460-466
Abstract

Stars that formed with an initial mass of over 50 M _⊙ are very rare today, but they are thought to be more common in the early Universe. The fates of those early, metal-poor, massive stars are highly uncertain. Most are expected to directly collapse to black holes, while some may explode as a result of rotationally powered engines or the pair-creation instability. We present the chemical abundances of J0931+0038, a nearby low-mass star identified in early follow-up of the SDSS-V Milky Way Mapper, which preserves the signature of unusual nucleosynthesis from a massive star in the early Universe. J0931+0038 has a relatively high metallicity ([Fe/H] = −1.76 ± 0.13) but an extreme odd–even abundance pattern, with some of the lowest known abundance ratios of [N/Fe], [Na/Fe], [K/Fe], [Sc/Fe], and [Ba/Fe]. The implication is that a majority of its metals originated in a single extremely metal-poor nucleosynthetic source. An extensive search through nucleosynthesis predictions finds a clear preference for progenitors with initial mass >50 M _⊙ , making J0931+0038 one of the first observational constraints on nucleosynthesis in this mass range. However, the full abundance pattern is not matched by any models in the literature. J0931+0038 thus presents a challenge for the next generation of nucleosynthesis models and motivates the study of high-mass progenitor stars impacted by convection, rotation, jets, and/or binary companions. Though rare, more examples of unusual early nucleosynthesis in metal-poor stars should be found in upcoming large spectroscopic surveys.

Published
2024
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2. The SDSS-V Local Volume Mapper Telescope System

Author

T. M. Herbst, Peter Bizenberger, Guillermo A. Blanc, Florian Briegel, Niv Drory, Cynthia S. Froning, Wolfgang Gaessler, Maximilian Häberle, Nicholas P. Konidaris, Markus Kuhlberg, Alicia Lanz, Richard Mathar, Lars Mohr, Solange Ramirez, Christopher Ritz, Ralf-Rainer Rohloff, José Sánchez-Gallego, Stefanie Wachter, Hojae Ahn, Felipe Besser, Scott Case, Tobias Feger, Anthony Hebert, Juna A. Kollmeier, Soojong Pak, Hans-Walter Rix, David Robertson, Paula Stępień, and Ross Zhelem

Subjects
Automated telescopes, Wide-field telescopes, Telescopes, Sky surveys, Astronomical instrumentation, Astronomy, QB1-991
Abstract

This paper presents the Local Volume Mapper (LVM) telescope system. LVM is one of three surveys that form the fifth generation of the Sloan Digital Sky Survey (SDSS-V), and it employs a coordinated network of four, 16 cm diameter telescopes feeding integral field units (IFUs) leading to three fiber spectrographs. One telescope hosts the science IFU, while two others observe adjacent fields to calibrate geocoronal emission. The fourth telescope makes rapid observations of bright stars to compensate for telluric absorption. The entrance slits of the spectrographs intersperse the fibers from all three types of telescope, producing truly simultaneous science and calibration exposures. We describe the final design of the telescope system and report on its construction, alignment and testing in the laboratory, as well as the integration, testing, commissioning, and actual on-sky performance at Las Campanas Observatory.

Published
2024
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3. The SDSS-V Local Volume Mapper (LVM): Scientific Motivation and Project Overview

Author

Niv Drory, Guillermo A. Blanc, Kathryn Kreckel, Sebastián F. Sánchez, Alfredo Mejía-Narváez, Evelyn J. Johnston, Amy M. Jones, Eric W. Pellegrini, Nicholas P. Konidaris, Tom Herbst, José Sánchez-Gallego, Juna A. Kollmeier, Florence de Almeida, Jorge K. Barrera-Ballesteros, Dmitry Bizyaev, Joel R. Brownstein, Mar Canal i Saguer, Brian Cherinka, Maria-Rosa L. Cioni, Enrico Congiu, Maren Cosens, Bruno Dias, John Donor, Oleg Egorov, Evgeniia Egorova, Cynthia S. Froning, Pablo García, Simon C. O. Glover, Hannah Greve, Maximilian Häberle, Kevin Hoy, Hector Ibarra, Jing Li, Ralf S. Klessen, Dhanesh Krishnarao, Nimisha Kumari, Knox S. Long, José Eduardo Méndez-Delgado, Silvia Anastasia Popa, Solange Ramirez, Hans-Walter Rix, Aurora Mata Sánchez, Ravi Sankrit, Natascha Sattler, Conor Sayres, Amrita Singh, Guy Stringfellow, Stefanie Wachter, Elizabeth Jayne Watkins, Tony Wong, and Aida Wofford

Subjects
Astronomical instrumentation, Stellar feedback, Interstellar medium, Sky surveys, Astronomy, QB1-991
Abstract

We present the Sloan Digital Sky Survey V Local Volume Mapper (LVM). The LVM is an integral-field spectroscopic survey of the Milky Way, Magellanic Clouds, and a sample of local volume galaxies, connecting resolved parsec-scale individual sources of feedback to kiloparsec-scale ionized interstellar medium (ISM) properties. The 4 yr survey covers the southern Milky Way disk at spatial resolutions of 0.05–1 pc, the Magellanic Clouds at 10 pc resolution, and nearby large galaxies at larger scales totaling >4300 deg ^2 of sky and more than 55M spectra. It utilizes a new facility of alt–alt mounted siderostats feeding 16 cm refractive telescopes, lenslet-coupled fiber optics, and spectrographs covering 3600–9800 Å at R ∼ 4000. The ultra-wide-field integral-field unit has a diameter of 0.°5 with 1801 hexagonally packed fibers of 35.″3 apertures. The siderostats allow for a completely stationary fiber system, avoiding instability of the line-spread function seen in traditional fiber feeds. Scientifically, LVM resolves the regions where energy, momentum, and chemical elements are injected into the ISM at the scale of gas clouds, while simultaneously charting where energy is being dissipated (via cooling, shocks, turbulence, bulk flows, etc.) to global scales. This combined local and global view enables us to constrain physical processes regulating how stellar feedback operates and couples to galactic kinematics and disk-scale structures, such as the bar and spiral arms, as well as gas in- and outflows.

Published
2024
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4. The Eighteenth Data Release of the Sloan Digital Sky Surveys: Targeting and First Spectra from SDSS-V

Author

Andrés Almeida, Scott F. Anderson, Maria Argudo-Fernández, Carles Badenes, Kat Barger, Jorge K. Barrera-Ballesteros, Chad F. Bender, Erika Benitez, Felipe Besser, Jonathan C. Bird, Dmitry Bizyaev, Michael R. Blanton, John Bochanski, Jo Bovy, William Nielsen Brandt, Joel R. Brownstein, Johannes Buchner, Esra Bulbul, Joseph N. Burchett, Mariana Cano Díaz, Joleen K. Carlberg, Andrew R. Casey, Vedant Chandra, Brian Cherinka, Cristina Chiappini, Abigail A. Coker, Johan Comparat, Charlie Conroy, Gabriella Contardo, Arlin Cortes, Kevin Covey, Jeffrey D. Crane, Katia Cunha, Collin Dabbieri, James W. Davidson Jr, Megan C. Davis, Anna Barbara de Andrade Queiroz, Nathan De Lee, José Eduardo Méndez Delgado, Sebastian Demasi, Francesco Di Mille, John Donor, Peter Dow, Tom Dwelly, Mike Eracleous, Jamey Eriksen, Xiaohui Fan, Emily Farr, Sara Frederick, Logan Fries, Peter Frinchaboy, Boris T. Gänsicke, Junqiang Ge, Consuelo González Ávila, Katie Grabowski, Catherine Grier, Guillaume Guiglion, Pramod Gupta, Patrick Hall, Keith Hawkins, Christian R. Hayes, J. J. Hermes, Lorena Hernández-García, David W. Hogg, Jon A. Holtzman, Hector Javier Ibarra-Medel, Alexander Ji, Paula Jofre, Jennifer A. Johnson, Amy M. Jones, Karen Kinemuchi, Matthias Kluge, Anton Koekemoer, Juna A. Kollmeier, Marina Kounkel, Dhanesh Krishnarao, Mirko Krumpe, Ivan Lacerna, Paulo Jakson Assuncao Lago, Chervin Laporte, Chao Liu, Ang Liu, Xin Liu, Alexandre Roman Lopes, Matin Macktoobian, Steven R. Majewski, Viktor Malanushenko, Dan Maoz, Thomas Masseron, Karen L. Masters, Gal Matijevic, Aidan McBride, Ilija Medan, Andrea Merloni, Sean Morrison, Natalie Myers, Szabolcs Mészáros, C. Alenka Negrete, David L. Nidever, Christian Nitschelm, Daniel Oravetz, Audrey Oravetz, Kaike Pan, Yingjie Peng, Marc H. Pinsonneault, Rick Pogge, Dan Qiu, Solange V. Ramirez, Hans-Walter Rix, Daniela Fernández Rosso, Jessie Runnoe, Mara Salvato, Sebastian F. Sanchez, Felipe A. Santana, Andrew Saydjari, Conor Sayres, Kevin C. Schlaufman, Donald P. Schneider, Axel Schwope, Javier Serna, Yue Shen, Jennifer Sobeck, Ying-Yi Song, Diogo Souto, Taylor Spoo, Keivan G. Stassun, Matthias Steinmetz, Ilya Straumit, Guy Stringfellow, José Sánchez-Gallego, Manuchehr Taghizadeh-Popp, Jamie Tayar, Ani Thakar, Patricia B. Tissera, Andrew Tkachenko, Hector Hernandez Toledo, Benny Trakhtenbrot, José G. Fernández-Trincado, Nicholas Troup, Jonathan R. Trump, Sarah Tuttle, Natalie Ulloa, Jose Antonio Vazquez-Mata, Pablo Vera Alfaro, Sandro Villanova, Stefanie Wachter, Anne-Marie Weijmans, Adam Wheeler, John Wilson, Leigh Wojno, Julien Wolf, Xiang-Xiang Xue, Jason E. Ybarra, Eleonora Zari, and Gail Zasowski

Subjects
Surveys, Astronomy databases, Astronomy data acquisition, Astronomy software, Astrophysics, QB460-466
Abstract

The eighteenth data release (DR18) of the Sloan Digital Sky Survey (SDSS) is the first one for SDSS-V, the fifth generation of the survey. SDSS-V comprises three primary scientific programs or “Mappers”: the Milky Way Mapper (MWM), the Black Hole Mapper (BHM), and the Local Volume Mapper. This data release contains extensive targeting information for the two multiobject spectroscopy programs (MWM and BHM), including input catalogs and selection functions for their numerous scientific objectives. We describe the production of the targeting databases and their calibration and scientifically focused components. DR18 also includes ∼25,000 new SDSS spectra and supplemental information for X-ray sources identified by eROSITA in its eFEDS field. We present updates to some of the SDSS software pipelines and preview changes anticipated for DR19. We also describe three value-added catalogs (VACs) based on SDSS-IV data that have been published since DR17, and one VAC based on the SDSS-V data in the eFEDS field.

Published
2023
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5. On-sky performance of the robotic Focal Plane Systems (FPS) for the Sloan Digital Sky Survey V

Author

Richard . Pogge, Mark Derwent, Christopher Brandon, Colby Jurgenson, Michael Engelman, Thomas P. O'Brien, Daniel Pappalardo, Julia Brady, Jacob McCloskey, Jonathan Shover, Jerry A. Mason, Ricardo Araujo, Mohamed Bouri, Jean-Paul Kneib, Luzius Kronig, Sarah . Tuttle, Emily Farr, José Sánchez-Gallego, Conor Sayres, Juna . Kollmeier, Solange Ramírez, Stefanie Wachter, Dmitry Bizyaev, Francis Cope, Katie Grabowski, Karen Kinemuchi, Viktor Malanushenko, Audrey Oravetz, Daniel Oravetz, Kaike Pan, Muwen Shi, Dylan Gatlin, Sophia Brunner, Felipe Besser, Consuelo Gonzalez Avila, Pablo Vera, Natalie Ulloa, and John Wilson

Published
2022
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9. The Sloan Digital Sky Survey cyberinfrastructure

Author

José Sánchez-Gallego, Brian Cherinka, Joel Brownstein, John Donor, Conor Sayres, Hojae Ahn, Changgon Kim, Juna A. Kollmeier, Nicholas P. Konidaris, Soojong Pak, Solange Ramírez, Shane Thomas, Stefanie Wachter, Mingyeong Yang, and Lionel Zumaran

Published
2022
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10. Construction, testing, and commissioning of the SDSS-V Local Volume Mapper telescope system

Author

Thomas M. Herbst, Peter Bizenberger, Guillermo A. Blanc, Florian Briegel, Scott Case, Niv Drory, Tobias Feger, Cynthia Froning, Wolfgang Gaessler, Maximilian Häberle, Anthony Hebert, Juna Kollmeier, Nicholas Konidaris, Markus Kuhlberg, Alicia Lanz, Richard Mathar, Lars Mohr, Soojong Pak, Solange Ramírez, Christopher Ritz, Ralf-Rainer Rohloff, José Sánchez-Gallego, Paula Stępień, Stefanie Wachter, Ross Zhelem, and Dmitry Bizyaev

Published
2022
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11. Covid - 19 : entre la justificación y la exculpación

Author

José Sánchez Gallego

Abstract

“Como consecuencia de ese incremento sostenido de casos, desde junio ha ido en aumento el número de pacientes, tanto en salas de hospitalización como en las unidades de cuidados intensivos, alcanzando el pasado viernes 714 pacientes hospitalizados en salas y 148 en las UCI. Situación que tiene al sistema de salud, incluido el personal que atiende a los enfermos al borde del colapso”. (Prosperi Ramírez, 2020).

Published
2020
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13. SDSS-V pioneering panoptic spectroscopy

Author

Juna Kollmeier, Anderson, S. F., Blanc, G. A., Blanton, M. R., Covey, K. R., Crane, J., Drory, N., Frinchaboy, P. M., Froning, C. S., Johnson, J. A., P Kneib, J., Kreckel, K., Merloni, A., Pellegrini, E. W., Pogge, R. W., Ramirez, S. V., Rix, H. W., Sayres, C., José Sánchez-Gallego, Yue Shen, Tkachenko, A., Trump, J. R., Tuttle, S. E., Anne-Marie Weijmans, Zasowski, G., Barbuy, B., Beaton, R. L., Bergemann, M., Bochanski, J. J., Brandt, W. N., Casey, A. R., Cherinka, B. A., Eracleous, M., Fan, X., García, R. A., Green, P. J., Hekker, S., Lane, R. R., Longa-Peña, P., Mathur, S., Meza, A., Minchev, I., Myers, A. D., Nidever, D. L., Nitschelm, C., Connell, J. E. O., Price-Whelan, A. M., Raddick, M. J., Rossi, G., Sankrit, R., Simon, J. D., Stutz, A. M., S Ting, Y., Trakhtenbrot, B., Weaver, B. A., Willmer, C. N. A., Weinberg, D. H., University of St Andrews. School of Physics and Astronomy, and University of St Andrews. Centre for Contemporary Art

Subjects
NDAS, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics::Galaxy Astrophysics
Abstract

This white paper presents the case for SDSS-V. SDSS-V is an unprecedented all-sky spectroscopic survey of over six million objects. It is designed to decode the history of the Milky Way galaxy, trace the emergence of the chemical elements, reveal the inner workings of galaxies and their stars, and investigate the origin of planets. Publisher PDF Non

Published
2019

14. Variability monitoring of OB stars during the Mons campaign

Author

A. M. T. Pollock, Berthold Stober, T. Bergmann, Eva M dos Santos, Michael F. Corcoran, Nelson G Correia Viegas, Peredur M. Williams, Johan H. Knapen, T. Hunger, Luis F Gouveia Carreira, Filipe Marques Dias, Julian M. Pittard, Grégor Rauw, Barbara Stober, Otmar Stahl, Thierry Morel, Thomas Eversberg, Filipe Alves, R. Leadbeater, A. Fernando, Kenji Hamaguchi, N. Romeo, José Luís Pais Ribeiro, Sean M. Dougherty, Klaus Vollmann, José Sánchez Gallego, N. Reinecke, Anthony F. J. Moffat, W. Arnold, L. Schanne, and R. Fahed

Subjects
Physics, Stars, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, FOS: Physical sciences, Astronomy, Astronomy and Astrophysics, Solar and Stellar Astrophysics (astro-ph.SR)
Abstract

We present preliminary results of a 3-month campaign carried out in the framework of the Mons project, where time-resolved Halpha observations are used to study the wind and circumstellar properties of a number of OB stars., 2 pages, 1 figure. To appear in proceedings of IAUS272 'Active OB Stars: Structure, Evolution, Mass Loss and Critical Limits'

Published
2010

15. Spectroscopic follow-up of the colliding-wind binary WR 140 during the 2009 January periastron passage

Author

Luis F Gouveia Carreira, André-Nicolas Chené, W. Arnold, R. Leadbeater, Julian M. Pittard, Klaus Vollmann, T. Hunger, Filipe Marques Dias, Juan Zorec, A. Fernando, Otmar Stahl, T. Bergmann, Grégor Rauw, Peredur M. Williams, Sean M. Dougherty, Berthold Stober, Barbara Stober, A. M. T. Pollock, N. Romeo, Thomas Eversberg, Anthony F. J. Moffat, Filipe Alves, Thierry Morel, José R. Ribeiro, José Sánchez Gallego, Michael F. Corcoran, L. Schanne, Johan H. Knapen, R. Fahed, N. Reinecke, Nelson G Correia Viegas, and Eva M dos Santos

Subjects
Physics, Colliding-wind binary, Orbital elements, Space and Planetary Science, media_common.quotation_subject, Astronomy, Astronomy and Astrophysics, Astrophysics, Eccentricity (behavior), media_common, O-type star
Abstract

We present the results from the spectroscopic follow-up of WR140 (WC7 + O4-5) during its last periastron passage in january 2009. This object is known as the archetype of colliding wind binaries and has a relatively large period (≃8 years) and eccentricity (≃0.89). We provide updated values for the orbital parameters, new estimates for the WR and O star masses and new constraints on the mass-loss rates.

Published
2010
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