Browsing by Author "Minniti, Dante"

Now showing 1 - 20 of 23
  • No Thumbnail Available
    Item
    An enquiry on the origins of N-rich stars in the inner Galaxy based on APOGEE chemical compositions
    (2021) Kisku, Shobhit; Schiavon, Ricardo P.; Horta, Danny; Mason, Andrew; Mackereth, J. Ted; Hasselquist, Sten; Garcia-Hernandez, D. A.; Bizyaev, Dmitry; Brownstein, Joel R.; Lane, Richard R.; Minniti, Dante; Pan, Kaike; Roman-Lopes, Alexandre
    Recent evidence based on APOGEE data for stars within a few kpc of the Galactic Centre suggests that dissolved globular clusters (GCs) contribute significantly to the stellar mass budget of the inner halo. In this paper, we enquire into the origins of tracers of GC dissolution, N-rich stars, that are located in the inner 4 kpc of the Milky Way. From an analysis of the chemical compositions of these stars, we establish that about 30 per cent of the N-rich stars previously identified in the inner Galaxy may have an accreted origin. This result is confirmed by an analysis of the kinematic properties of our sample. The specific frequency of N-rich stars is quite large in the accreted population, exceeding that of its in situ counterparts by near an order of magnitude, in disagreement with predictions from numerical simulations. We hope that our numbers provide a useful test to models of GC formation and destruction.
  • No Thumbnail Available
    Item
    Disentangling the Galactic Halo with APOGEE. I. Chemical and Kinematical Investigation of Distinct Metal-poor Populations
    (2018) Hayes, Christian R.; Majewski, Steven R.; Shetrone, Matthew; Fernandez-Alvar, Emma; Allende Prieto, Carlos; Schuster, William J.; Carigi, Leticia; Cunha, Katia; Smith, Verne V.; Sobeck, Jennifer; Almeida, Andres; Beers, Timothy C.; Carrera, Ricardo; Fernandez-Trincado, J. G.; Garcia-Hernandez, D. A.; Geisler, Doug; Lane, Richard R.; Lucatello, Sara; Matthews, Allison M.; Minniti, Dante; Nitschelm, Christian; Tang, Baitian; Tissera, Patricia B.; Zamora, Olga
    We find two chemically distinct populations separated relatively cleanly in the [Fe/H]-[Mg/Fe] plane, but also distinguished in other chemical planes, among metal-poor stars (primarily with metallicities [Fe/H] < -0.9) observed by the Apache Point Observatory Galactic Evolution Experiment (APOGEE) and analyzed for Data Release 13 (DR13) of the Sloan Digital Sky Survey. These two stellar populations show the most significant differences in their [X/Fe] ratios for the alpha-elements, C+N, Al, and Ni. In addition to these populations having differing chemistry, the low metallicity high-Mg population (which we denote "the HMg population") exhibits a significant net Galactic rotation, whereas the low-Mg population (or "the LMg population") has halo-like kinematics with little to no net rotation. Based on its properties, the origin of the LMg population is likely an accreted population of stars. The HMg population shows chemistry (and to an extent kinematics) similar to the thick disk, and is likely associated with in situ formation. The distinction between the LMg and HMg populations mimics the differences between the populations of low-and high-a halo stars found in previous studies, suggesting that these are samples of the same two populations.
  • No Thumbnail Available
    Item
    Final Targeting Strategy for the SDSS-IV APOGEE-2S Survey
    (2021) Santana, Felipe A.; Beaton, Rachael L.; Covey, Kevin R.; O'Connell, Julia E.; Longa-Pena, Penelope; Cohen, Roger; Fernandez-Trincado, Jose G.; Hayes, Christian R.; Zasowski, Gail; Sobeck, Jennifer S.; Majewski, Steven R.; Chojnowski, S. D.; De Lee, Nathan; Oelkers, Ryan J.; Stringfellow, Guy S.; Almeida, Andres; Anguiano, Borja; Donor, John; Frinchaboy, Peter M.; Hasselquist, Sten; Johnson, Jennifer A.; Kollmeier, Juna A.; Nidever, David L.; Price-Whelan, Adrian M.; Rojas-Arriagada, Alvaro; Schultheis, Mathias; Shetrone, Matthew; Simon, Joshua D.; Aerts, Conny; Borissova, Jura; Drout, Maria R.; Geisler, Doug; Law, C. Y.; Medina, Nicolas; Minniti, Dante; Monachesi, Antonela; Munoz, Ricardo R.; Poleski, Radoslaw; Roman-Lopes, Alexandre; Schlaufman, Kevin C.; Stutz, Amelia M.; Teske, Johanna; Tkachenko, Andrew; Van Saders, Jennifer L.; Weinberger, Alycia J.; Zoccali, Manuela
    APOGEE is a high-resolution (R similar to 22,000), near-infrared, multi-epoch, spectroscopic survey of the Milky Way. The second generation of the APOGEE project, APOGEE-2, includes an expansion of the survey to the Southern Hemisphere called APOGEE-2S. This expansion enabled APOGEE to perform a fully panoramic mapping of all of the main regions of the Milky Way; in particular, by operating in the H band, APOGEE is uniquely able to probe the dust-hidden inner regions of the Milky Way that are best accessed from the Southern Hemisphere. In this paper we present the targeting strategy of APOGEE-2S, with special attention to documenting modifications to the original, previously published plan. The motivation for these changes is explained as well as an assessment of their effectiveness in achieving their intended scientific objective. In anticipation of this being the last paper detailing APOGEE targeting, we present an accounting of all such information complete through the end of the APOGEE-2S project; this includes several main survey programs dedicated to exploration of major stellar populations and regions of the Milky Way, as well as a full list of programs contributing to the APOGEE database through allocations of observing time by the Chilean National Time Allocation Committee and the Carnegie Institution for Science. This work was presented along with a companion article, Beaton et al. (2021), presenting the final target selection strategy adopted for APOGEE-2 in the Northern Hemisphere.
  • No Thumbnail Available
    Item
    How many components? Quantifying the complexity of the metallicity distribution in the Milky Way bulge with APOGEE
    (2020) Rojas-Arriagada, Alvaro; Zasowski, Gail; Schultheis, Mathias; Zoccali, Manuela; Hasselquist, Sten; Chiappini, Cristina; Cohen, Roger E.; Cunha, Katia; Fernandez-Trincado, Jose G.; Fragkoudi, Francesca; Garcia-Hernandez, D. A.; Geisler, Doug; Gran, Felipe; Lian, Jianhui; Majewski, Steven; Minniti, Dante; Monachesi, Antonela; Nitschelm, Christian; Queiroz, Anna B. A.
    We use data of similar to 13 000 stars from the Sloan Digital Sky Survey/Apache Point Observatory Galactic Evolution Experiment survey to study the shape of the bulge metallicity distribution function (MDF) within the region vertical bar l vertical bar <= 11 degrees and vertical bar b vertical bar = 13 degrees, and spatially constrained to R-GC <= 3.5 kpc. We apply Gaussian mixture modelling and non-negative matrix factorization decomposition techniques to identify the optimal number and the properties of MDF components. We find that the shape and spatial variations of the MDF (at [Fe/H] >= -1 dex) are well represented as a smoothly varying contribution of three overlapping components located at [Fe/H] = +0.32, -0.17, and -0.66 dex. The bimodal MDF found in previous studies is in agreement with our trimodal assessment once the limitations in sample size and individual measurement errors are taken into account. The shape of the MDF and its correlations with kinematics reveal different spatial distributions and kinematical structure for the three components co-existing in the bulge region. We confirm the consensus physical interpretation of metal-rich stars as associated with the secularly evolved disc into a boxy/peanut X-shape bar. On the other hand, metal-intermediate stars could be the product of in-situ formation at high redshift in a gas-rich environment characterized by violent and fast star formation. This interpretation would help us to link a present-day structure with those observed in formation in the centre of high-redshift galaxies. Finally, metal-poor stars may correspond to the metal-rich tail of the population sampled at lower metallicity from the study of RR Lyrae stars. Conversely, they could be associated with the metal-poor tail of the early thick disc.
  • No Thumbnail Available
    Item
    HST photometry of the binary globular cluster sersic 13N-S in NGC5128[1]
    (2009) Villegas Mansilla, Daniela Muriel; Minniti, Dante; Funes, J. G.; Richtler, Tom; Larsen, Søren
  • No Thumbnail Available
    Item
    Millimagnitude photometry for transiting extrasolar planetary candidates.: II. transits of OGLE-TR-113-B in the optical and near-ir
    (2007) Diaz, Rodrigo F.; Ramirez, Sebastían; Fernandez, José Miguel; Gallardo, José; Gieren, Wolfgang; Ivanov, Valentin D.; Mauas, Pablo; Minniti, Dante; Pietrzynski, Grzegorz; Perez, Felipe; Ruiz, Maria Teresa; Udalski, Andrzej; Zoccali, Manuela
    We present precise V-and K-s-band transit photometry for the planetary host star OGLE-TR-113. Using the Ks-band photometry, we confirm the dwarf nature of OGLE-TR-113 and obtain new estimates for its effective temperature, distance, and reddening. We employ the V-band photometry to obtain planetary and orbit parameters from the transit fit, alpha = 0.0232 +/- 0: 0038 AU, orbital period P = 1.4324752 +/- 0.0000015 day, i = 86.7-90, and R-p 1.09 +/- 0.09 R-J. These values are in excellent agreement with previous works. Assuming a mass M-p 1.32 +/- 0.19 M-J for the planet, we obtain its mean density p = 1.26 +/- 0.50 g cm(-3), also in agreement with previous works. The transit observed in the K-s-band has a larger scatter, and we find its amplitude to be consistent with that in the V band. In this way, we find an independent confirmation of the planetary nature of OGLE-TR-113b.
  • No Thumbnail Available
    Item
    Millimagnitude photometry for transiting extrasolar planetary candidates.: III. accurate radius and period for OGLE-TR-111-B
    (2007) Minniti, Dante; Fernandez, José Miguel; Diaz, Rodrigo F.; Udalski, Andrzej; Pietrzynski, Grzegorz; Gieren, Wolfgang; Rojo, Patricio; Ruiz, María Teresa; Zoccali, Manuela
    We present accurate V-band photometry for a planetary transit of OGLE-TR-111 acquired with VIMOS at the ESO Very Large Telescope. The measurement of this transit allows us to refine the planetary radius, obtaining R-p 1.01 +/- 0.06 R-J. Given the mass of M-p 0.53 M-J previously measured from radial velocities, we confirm that the density is p(p) = 0.6 +/- 0.2 g cm(-3). We also revise the ephemeris for OGLE-TR-111-b, obtaining an accurate orbital period P = 4.014484 +/- 0.000014 days and predicting that the next observable transits would occur around December 2006, and after that only in mid-2008. Even though this period is different from previously published values, we cannot yet rule out a constant period.
  • No Thumbnail Available
    Item
    PEERING THROUGH THE DUST: PRECISE ASTROMETRY IN THE GALACTIC MID-PLANE WITH THE VVV SURVEY
    (2015) Lucas, PW; Smart, RL; Jones, HRA; Kurtev, R; Beamin Muhlenbrock, Juan Carlos; Borissova, J.; Gromadzki, Grzegorz; Ivanov, Valentin; Minniti, Dante; Pinfield, DJ
    Gaia will see little of the Galactic mid-plane and nuclear bulge due to high extinction at optical wavelengths. To study the structure and kinematics of the inner Galaxy we must look to longer wavelengths. The Vista Variables in the Via Lactea (VVV, Minniti et al. 2010) survey currently provides just over 4 years of observations covering approximately 560 square degrees of the Galactic bulge and plane. Typically each source is observed 50-150 times in the Ks band over this period. Using these data we provide relative proper motions for approximately 200 million unique sources down to Ks similar to 16 with uncertainties approaching 1 mas yr(-1). In addition, we fit a solution of the parallactic motion of all sources with significant proper motion and discover a number of new nearby brown dwarfs. These results will allow us to identify faint common proper motion companions to stars with Gaia parallaxes, increasing the number of brown dwarf benchmark objects. Our absolute astrometric calibration precision is currently similar to 2 mas yr(-1), based on PPMXL. The Gaia absolute astrometric reference grid will allow us to precisely anchor our results and measure the streaming motions of stars in the bulge. Finally, we anticipate that the catalogue could provide kinematic distances to the numerous optically invisible high amplitude variable stars that VVV is discovering.
  • No Thumbnail Available
    Item
    Proper motions and brown dwarfs in the VVV survey
    (2014) Beamín Muhlenbrock, Juan Carlos; Minniti, Dante; Gromadzki, M.; Kurtev, R.; Ivanov, V. D.; Peña Ramírez, Karla Yulien; Saito, R. K.; Borissova, J.
    We use the first three years of observations of the VISTA Variables in the Via Lactea Survey, to create a catalog of high proper motion objects, and search for nearby objects, here we describe the initial results including the discovery the first brown dwarf in the VVV survey.
  • No Thumbnail Available
    Item
    Proper motions of dwarf spheroidal galaxies from Hubble Space Telescope imaging.: V.: Final measurement for Fornax
    (2007) Piatek, Slawomir; Pryor, Carlton; Bristow, Paul; Olszewski, Edward W.; Harris, Hugh C.; Mateo, Mario; Minniti, Dante; Tinney, Christopher G.
    The measured proper motion of Fornax, expressed in the equatorial coordinate system, is (mu(alpha), mu(delta)) = (47.6 +/- 4.6, -36.0 +/- 4.1) mas century(-1). This proper motion is a weighted mean of four independent measurements for three distinct fields. Each measurement uses a quasi-stellar object as a reference point. Removing the contribution of the motion of the Sun and of the local standard of rest to the measured proper motion produces a Galactic rest-frame proper motion of (mu(Grf)(alpha), mu(Grf)(delta)) = (24.4 +/- 4.6, -14.3 +/- 4.1) mas century(-1). The implied space velocity with respect to the Galactic center has a radial component of V-r = -31.8 +/- 1.7 km s(-1) and a tangential component of V-t = 196 +/- 29 km s(-1). Integrating the motion of Fornax in a realistic potential for the Milky Way produces orbital elements. The perigalacticon and apogalacticon are 118 ( 66, 137) and 152 ( 144, 242) kpc, respectively, where the values in the parentheses represent the 95% confidence intervals derived from Monte Carlo experiments. The eccentricity of the orbit is 0.13 (0.11, 0.38), and the orbital period is 3.2 (2.5, 4.6) Gyr. The orbit is retrograde and inclined by 101 degrees ( 94 degrees, 107 degrees) to the Galactic plane. Fornax could be a member of a proposed "stream'' of galaxies and globular clusters; however, the membership of another proposed galaxy in the stream, Sculptor, has been previously ruled out. Fornax is in the Kroupa-Theis-Boily plane, which contains 11 of the Galactic satellite galaxies, but its orbit will take it out of that plane.
  • Thumbnail Image
    Item
    Properties of RR Lyrae stars in the inner regions of the Large Magellanic Cloud. II. The extended sample
    (2007) Borissova, J.; Minniti, Dante; Rejkuba, M.; Alves, D.
  • Thumbnail Image
    Item
    Pulsating stars in ω Centauri. Near-IR properties and period-luminosity relations
    (2017) Navarrete, Camila; Catelan, Marcio; Contreras Ramos, Rodrigo; Alonso-García, Javier; Gran, Felipe; Dékány, István; Minniti, Dante
    ω Centauri (NGC 5139) contains many variable stars of different types, including the pulsating type II Cepheids, RR Lyrae and SX Phoenicis stars. We carried out a deep, wide-field, near-infrared (IR) variability survey of ω Cen, using the VISTA telescope. We assembled an unprecedented homogeneous and complete J and KS near-IR catalog of variable stars in the field of ω Cen. In this paper we compare optical and near-IR light curves of RR Lyrae stars, emphasizing the main differences. Moreover, we discuss the ability of near-IR observations to detect SX Phoenicis stars given the fact that the amplitudes are much smaller in these bands compared to the optical. Finally, we consider the case in which all the pulsating stars in the three different variability types follow a single period-luminosity relation in the near-IR bands....
  • No Thumbnail Available
    Item
    Searching for extragalactic sources in the VISTA variables in the VÍa láctea survey
    (2018) Baravalle, Laura D.; Victoria Alonso, M.; Castellón, José Luis Nilo; Beamin Muhlenbrock, Juan Carlos; Minniti, Dante
    We search for extragalactic sources in the VISTA Variables in the Vía Láctea survey that are hidden by the Galaxy. Herein, we describe our photometric procedure to find and characterize extragalactic objects using a combination of SExtractor and PSFEx. It was applied in two tiles of the survey: d010 and d115, without previous extragalactic IR detections, in order to obtain photometric parameters of the detected sources. The adopted criteria to define extragalactic candidates include CLASS-STAR < 0.3; 1.0 < R1 2 < 5.0 arcsec; 2.1 < C < 5; and F > 0.002 and the colors: 0.5 < (J-Ks) < 2.0 mag; 0.0 < (J-H) < 1.0 mag; 0.0 < (H-Ks) < 2.0 mag and (J-H) + 0.9 (H-Ks) > 0.44 mag. We detected 345 and 185 extragalactic candidates in the d010 and d115 tiles, respectively. All of them were visually inspected and confirmed to be galaxies. In general, they are small and more circular objects, due to the near-IR sensitivity to select more compact objects with higher surface brightness. The procedure will be used to identify extragalactic objects in other tiles of the VVV disk, which will allow us to study the distribution of galaxies and filaments hidden by the Milky Way. © 2018. The American Astronomical Society. All rights reserved.
  • No Thumbnail Available
    Item
    Stellar proper motions in the Galactic bulge from deep Hubble Space Telescope ACS WFC photometry
    (2008) Clarkson, Will; Sahu, Kailash; Anderson, Jay; Smith, T. Ed; Brown, Thomas M.; Rich, R. Michael; Casertano, Stefano; Bond, Howard E.; Livio, Mario; Minniti, Dante; Panagia, Nino; Renzini, Alvio; Valenti, Jeff; Zoccali, Manuela
    We present stellar proper motions in the Galactic bulge from the Sagittarius Window Eclipsing Extrasolar Search ( SWEEPS) project using ACS WFC on HST. Proper motions are extracted for more than 180,000 objects, with > 81,000 measured to accuracy better than 0.3 mas yr(-1) in both coordinates. We report several results based on these measurements: ( 1) Kinematic separation of bulge from disk allows a sample of > 15,000 bulge objects to be extracted based on > 6 sigma detections of proper motion, with < 0.2% contamination from the disk. This includes the first detection of a candidate bulge blue straggler population. ( 2) Armed with a photometric distance modulus on a star-by-star basis, and using the large number of stars with high-quality proper-motion measurements to overcome intrinsic scatter, we dissect the kinematic properties of the bulge as a function of distance along the line of sight. This allows us to extract the stellar circular speed curve from proper motions alone, which we compare with the circular speed curve obtained from radial velocities. ( 3) We trace the variation of the {l, b} velocity ellipse as a function of depth. ( 4) Finally, we use the density-weighted {l, b} proper-motion ellipse produced from the tracer stars to assess the kinematic membership of the 16 transiting planet candidates discovered in the Sagittarius Window; the kinematic distribution of the planet candidates is consistent with that of the disk and bulge stellar populations.
  • No Thumbnail Available
    Item
    Stellar Variability in the VVV Survey: Highlights and Current Status
    (2015) Catelan, Marcio; Dékány, István; Minniti, Dante; Alonso-Garcia, Javier; Contreras Ramos, Rodrigo; Saito, Roberto; Hajdu, Gergely; Lucas, Phil; Kerins, Eamonn; Hempel, Maren
    The Vista Variables in the Via Lactea (VVV) ESO Public Survey consists in a near-infrared time-series survey of the Galactic bulge and inner disk, covering 562 square degrees of the sky, over a total timespan of more than 5 years. In this contribution, we discuss some of our latest results, and provide an updated account of the current status of the survey, especially in the context of stellar variability studies....
  • No Thumbnail Available
    Item
    The 16th Data Release of the Sloan Digital Sky Surveys: First Release from the APOGEE-2 Southern Survey and Full Release of eBOSS Spectra
    (2020) Ahumada, Romina; Allende Prieto, Carlos; Almeida, Andres; Anders, Friedrich; Anderson, Scott F.; Andrews, Brett H.; Anguiano, Borja; Arcodia, Riccardo; Armengaud, Eric; Aubert, Marie; Avila, Santiago; Avila-Reese, Vladimir; Badenes, Carles; Balland, Christophe; Barger, Kat; Barrera-Ballesteros, Jorge K.; Basu, Sarbani; Bautista, Julian; Beaton, Rachael L.; Beers, Timothy C.; Benavides, B. Izamar T.; Bender, Chad F.; Bernardi, Mariangela; Bershady, Matthew; Beutler, Florian; Bidin, Christian Moni; Bird, Jonathan; Bizyaev, Dmitry; Blanc, Guillermo A.; Blanton, Michael R.; Boquien, Mederic; Borissova, Jura; Bovy, Jo; Brandt, W. N.; Brinkmann, Jonathan; Brownstein, Joel R.; Bundy, Kevin; Bureau, Martin; Burgasser, Adam; Burtin, Etienne; Cano-Diaz, Mariana; Capasso, Raffaella; Cappellari, Michele; Carrera, Ricardo; Chabanier, Solene; Chaplin, William; Chapman, Michael; Cherinka, Brian; Chiappini, Cristina; Choi, Peter Doohyun; Chojnowski, S. Drew; Chung, Haeun; Clerc, Nicolas; Coffey, Damien; Comerford, Julia M.; Comparat, Johan; da Costa, Luiz; Cousinou, Marie-Claude; Covey, Kevin; Crane, Jeffrey D.; Cunha, Katia; Ilha, Gabriele da Silva; Dai, Yu Sophia; Damsted, Sanna B.; Darling, Jeremy; Davidson, James W., Jr.; Davies, Roger; Dawson, Kyle; De, Nikhil; de la Macorra, Axel; Lee, Nathan De; de Andrade Queiroz, Anna Barbara; Machado, Alice Deconto; de la Torre, Sylvain; Dell'Agli, Flavia; des Bourboux, Helion du Mas; Diamond-Stanic, Aleksandar M.; Dillon, Sean; Donor, John; Drory, Niv; Duckworth, Chris; Dwelly, Tom; Ebelke, Garrett; Eftekharzadeh, Sarah; Eigenbrot, Arthur Davis; Elsworth, Yvonne P.; Eracleous, Mike; Erfanianfar, Ghazaleh; Escoffier, Stephanie; Fan, Xiaohui; Farr, Emily; Fernandez-Trincado, Jose G.; Feuillet, Diane; Finoguenov, Alexis; Fofie, Patricia; Fraser-McKelvie, Amelia; Frinchaboy, Peter M.; Fromenteau, Sebastien; Fu, Hai; Galbany, Lluis; Garcia, Rafael A.; Garcia-Hernandez, D. A.; Oehmichen, Luis Alberto Garma; Ge, Junqiang; Maia, Marcio Antonio Geimba; Geisler, Doug; Gelfand, Joseph; Goddy, Julian; Gonzalez-Perez, Violeta; Grabowski, Kathleen; Green, Paul; Grier, Catherine J.; Guo, Hong; Guy, Julien; Harding, Paul; Hasselquist, Sten; Hawken, Adam James; Hayes, Christian R.; Hearty, Fred; Hekker, S.; Hogg, David W.; Holtzman, Jon A.; Horta, Danny; Hou, Jiamin; Hsieh, Bau-Ching; Huber, Daniel; Hunt, Jason A. S.; Chitham, J. Ider; Imig, Julie; Jaber, Mariana; Angel, Camilo Eduardo Jimenez; Johnson, Jennifer A.; Jones, Amy M.; Jonsson, Henrik; Jullo, Eric; Kim, Yerim; Kinemuchi, Karen; Iv, Charles C. Kirkpatrick; Kite, George W.; Klaene, Mark; Kneib, Jean-Paul; Kollmeier, Juna A.; Kong, Hui; Kounkel, Marina; Krishnarao, Dhanesh; Lacerna, Ivan; Lan, Ting-Wen; Lane, Richard R.; Law, David R.; Le Goff, Jean-Marc; Leung, Henry W.; Lewis, Hannah; Li, Cheng; Lian, Jianhui; Lin, Lihwai; Long, Dan; Longa-Pena, Penelope; Lundgren, Britt; Lyke, Brad W.; Mackereth, J. Ted; MacLeod, Chelsea L.; Majewski, Steven R.; Manchado, Arturo; Maraston, Claudia; Martini, Paul; Masseron, Thomas; Masters, Karen L.; Mathur, Savita; McDermid, Richard M.; Merloni, Andrea; Merrifield, Michael; Meszaros, Szabolcs; Miglio, Andrea; Minniti, Dante; Minsley, Rebecca; Miyaji, Takamitsu; Mohammad, Faizan Gohar; Mosser, Benoit; Mueller, Eva-Maria; Muna, Demitri; Munoz-Gutierrez, Andrea; Myers, Adam D.; Nadathur, Seshadri; Nair, Preethi; Nandra, Kirpal; do Nascimento, Janaina Correa; Nevin, Rebecca Jean; Newman, Jeffrey A.; Nidever, David L.; Nitschelm, Christian; Noterdaeme, Pasquier; O'Connell, Julia E.; Olmstead, Matthew D.; Oravetz, Daniel; Oravetz, Audrey; Osorio, Yeisson; Pace, Zachary J.; Padilla, Nelson; Palanque-Delabrouille, Nathalie; Palicio, Pedro A.; Pan, Hsi-An; Pan, Kaike; Parker, James; Paviot, Romain; Peirani, Sebastien; Ramirez, Karla Pena; Penny, Samantha; Percival, Will J.; Perez-Fournon, Ismael; Perez-Rafols, Ignasi; Petitjean, Patrick; Pieri, Matthew M.; Pinsonneault, Marc; Poovelil, Vijith Jacob; Povick, Joshua Tyler; Prakash, Abhishek; Price-Whelan, Adrian M.; Raddick, M. Jordan; Raichoor, Anand; Ray, Amy; Rembold, Sandro Barboza; Rezaie, Mehdi; Riffel, Rogemar A.; Riffel, Rogerio; Rix, Hans-Walter; Robin, Annie C.; Roman-Lopes, A.; Roman-Zuniga, Carlos; Rose, Benjamin; Ross, Ashley J.; Rossi, Graziano; Rowlands, Kate; Rubin, Kate H. R.; Salvato, Mara; Sanchez, Ariel G.; Sanchez-Menguiano, Laura; Sanchez-Gallego, Jose R.; Sayres, Conor; Schaefer, Adam; Schiavon, Ricardo P.; Schimoia, Jaderson S.; Schlafly, Edward; Schlegel, David; Schneider, Donald P.; Schultheis, Mathias; Schwope, Axel; Seo, Hee-Jong; Serenelli, Aldo; Shafieloo, Arman; Shamsi, Shoaib Jamal; Shao, Zhengyi; Shen, Shiyin; Shetrone, Matthew; Shirley, Raphael; Aguirre, Victor Silva; Simon, Joshua D.; Skrutskie, M. F.; Slosar, Anze; Smethurst, Rebecca; Sobeck, Jennifer; Sodi, Bernardo Cervantes; Souto, Diogo; Stark, David, V; Stassun, Keivan G.; Steinmetz, Matthias; Stello, Dennis; Stermer, Julianna; Storchi-Bergmann, Thaisa; Streblyanska, Alina; Stringfellow, Guy S.; Stutz, Amelia; Suarez, Genaro; Sun, Jing; Taghizadeh-Popp, Manuchehr; Talbot, Michael S.; Tayar, Jamie; Thakar, Aniruddha R.; Theriault, Riley; Thomas, Daniel; Thomas, Zak C.; Tinker, Jeremy; Tojeiro, Rita; Toledo, Hector Hernandez; Tremonti, Christy A.; Troup, Nicholas W.; Tuttle, Sarah; Unda-Sanzana, Eduardo; Valentini, Marica; Vargas-Gonzalez, Jaime; Vargas-Magana, Mariana; Vazquez-Mata, Jose Antonio; Vivek, M.; Wake, David; Wang, Yuting; Weaver, Benjamin Alan; Weijmans, Anne-Marie; Wild, Vivienne; Wilson, John C.; Wilson, Robert F.; Wolthuis, Nathan; Wood-Vasey, W. M.; Yan, Renbin; Yang, Meng; Yeche, Christophe; Zamora, Olga; Zarrouk, Pauline; Zasowski, Gail; Zhang, Kai; Zhao, Cheng; Zhao, Gongbo; Zheng, Zheng; Zheng, Zheng; Zhu, Guangtun; Zou, Hu
    This paper documents the 16th data release (DR16) from the Sloan Digital Sky Surveys (SDSS), the fourth and penultimate from the fourth phase (SDSS-IV). This is the first release of data from the Southern Hemisphere survey of the Apache Point Observatory Galactic Evolution Experiment 2 (APOGEE-2); new data from APOGEE-2 North are also included. DR16 is also notable as the final data release for the main cosmological program of the Extended Baryon Oscillation Spectroscopic Survey (eBOSS), and all raw and reduced spectra from that project are released here. DR16 also includes all the data from the Time Domain Spectroscopic Survey and new data from the SPectroscopic IDentification of ERosita Survey programs, both of which were co-observed on eBOSS plates. DR16 has no new data from the Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey (or the MaNGA Stellar Library "MaStar"). We also preview future SDSS-V operations (due to start in 2020), and summarize plans for the final SDSS-IV data release (DR17).
  • Thumbnail Image
    Item
    The most variable VVV sources: eruptive protostars, dipping giants in the Nuclear Disc and others
    (2023) Lucas, Phil; Smith, Leigh; Guo, Zhen; Contreras Peña, Carlos; Minniti, Dante; Miller, Niall; Alonso-Garcia, Javier; Catelan, Marcio; Borissova, J.; Saito, Roberto; Kurtev, Radostin; Navarro, M. G.; Morris, Calum; Muthu, Hariharan; Froebrich, Dirk; Ivanov, Valentin; Bayo, Amelia; Caratti, Alessio; Sanders, Jason
    We have performed a comprehensive search of a VISTA Variables in the Via Lactea (VVV) data base of 9.5 yr light curves for variable sources with ΔKs ≥ 4 mag, aiming to provide a large sample of high amplitude eruptive young stellar objects (YSOs) and detect unusual or new types of infrared variable source. We find 222 variable or transient sources in the Galactic bulge and disc, most of which are new discoveries. The sample mainly comprises novae, YSOs, microlensing events, Long Period Variable stars (LPVs), and a few rare or unclassified sources. Additionally, we report the discovery of a significant population of aperiodic late-type giant stars suffering deep extinction events, strongly clustered in the Nuclear Disc of the Milky Way. We suggest that these are metal-rich stars in which radiatively driven mass loss has been enhanced by super-solar metallicity. Among the YSOs, 32/40 appear to be undergoing episodic accretion. Long-lasting YSO eruptions have a typical rise time of ∼2 yr, somewhat slower than the 6–12 month time-scale seen in the few historical events observed on the rise. The outburst durations are usually at least 5 yr, somewhat longer than many lower amplitude VVV events detected previously. The light curves are diverse in nature, suggesting that multiple types of disc instability may occur. Eight long-duration extinction events are seen wherein the YSO dims for a year or more, attributable to inner disc structure. One binary YSO in NGC 6530 displays periodic extinction events (P=59 d) similar to KH 15D.
  • No Thumbnail Available
    Item
    The Open Cluster Chemical Abundances and Mapping Survey. IV. Abundances for 128 Open Clusters Using SDSS/APOGEE DR16
    (2020) Donor, John; Frinchaboy, Peter M.; Cunha, Katia; O'Connell, Julia E.; Prieto, Carlos Allende; Almeida, Andres; Anders, Friedrich; Beaton, Rachael; Bizyaev, Dmitry; Brownstein, Joel R.; Carrera, Ricardo; Chiappini, Cristina; Cohen, Roger; Garcia-Hernandez, D. A.; Geisler, Doug; Hasselquist, Sten; Jonsson, Henrik; Lane, Richard R.; Majewski, Steven R.; Minniti, Dante; Bidin, Christian Moni; Pan, Kaike; Roman-Lopes, Alexandre; Sobeck, Jennifer S.; Zasowski, Gail
    The Open Cluster Chemical Abundances and Mapping (OCCAM) survey aims to constrain key Galactic dynamical and chemical evolution parameters by the construction of a large, comprehensive, uniform, infrared-based spectroscopic data set of hundreds of open clusters. This fourth contribution from the OCCAM survey presents analysis using Sloan Digital Sky Survey/APOGEE DR16 of a sample of 128 open clusters, 71 of which we designate to be "high quality" based on the appearance of their color-magnitude diagram. We find the APOGEE DR16 derived [Fe/H] abundances to be in good agreement with previous high-resolution spectroscopic open cluster abundance studies. Using the high-quality sample, we measure Galactic abundance gradients in 16 elements, and find evolution of some of the [X/Fe] gradients as a function of age. We find an overall Galactic [Fe/H] versus R-GC gradient of -0.068 0.001 dex kpc(-1) over the range of 6 R-GC < 13.9 kpc; however, we note that this result is sensitive to the distance catalog used, varying as much as 15%. We formally derive the location of a break in the [Fe/H] abundance gradient as a free parameter in the gradient fit for the first time. We also measure significant Galactic gradients in O, Mg, S, Ca, Mn, Cr, Cu, Na, Al, and K, some of which are measured for the first time. Our large sample allows us to examine four well-populated age bins in order to explore the time evolution of gradients for a large number of elements and comment on possible implications for Galactic chemical evolution and radial migration.
  • No Thumbnail Available
    Item
    The RR Lyrae projected density distribution from the Galactic centre to the halo
    (2021) Gabriela Navarro, Maria; Minniti, Dante; Capuzzo-Dolcetta, Roberto; Alonso-Garcia, Javier; Contreras Ramos, Rodrigo; Majaess, Daniel; Ripepi, Vincenzo
    The projected density distribution of type ab RR Lyrae (RRab) stars was characterised from the innermost regions of the Milky Way to the halo, with the aim of placing constraints on the Galaxy's evolution. The compiled sample (N-RRab=64 850) stems from fundamental mode RR Lyrae variables identified by the VVV, OGLE, and Gaia surveys. The distribution is well fitted by three power laws over three radial intervals. In the innermost region (R<2.2) the distribution follows Sigma (RRab[1])proportional to R-0.94 +/- 0.051, while in the external region the distribution adheres to Sigma (RRab[2])proportional to R-1.50 +/- 0.019 for 2.2 degrees< R< 8.0 degrees and Sigma (RRab[3])proportional to R-2.43 +/- 0.043 for 8.0 degrees< R<30.0 degrees. Conversely, the cumulative distribution of red clump (RC) giants exhibits a more concentrated distribution in the mean, but in the central R<2.2 the RRab population is more peaked, whereas globular clusters (GCs) follow a density power law (Sigma (GCs)proportional to R-1.59 +/- 0.060 for R<30.0) similar to that of RRab stars, especially when considering a more metal-poor subsample ([Fe/H] < -1.1 dex). The main conclusion emerging from the analysis is that the RRab distribution favours the star cluster infall and merger scenario for creating an important fraction (> 18%) of the central Galactic region. The radii containing half of the populations (half populations radii) are R-H RRab=6.8 degrees (0.99 kpc), R-H RC=4.2 degrees (0.61 kpc), and R-H GCs=11.9 degrees (1.75 kpc) for the RRab stars, RC giants, and GCs, respectively. Finally, merely similar to 1% of the stars have been actually discovered in the innermost region (R< 35 pc) out of the expected (based on our considerations) total number of RRab therein: N1562. That deficit will be substantially ameliorated with future space missions like the Nancy Grace Roman Space Telescope (formerly WFIRST).
  • No Thumbnail Available
    Item
    The Seventeenth Data Release of the Sloan Digital Sky Surveys: Complete Release of MaNGA, MaStar, and APOGEE-2 Data
    (2022) Abdurro'uf; Accetta, Katherine; Aerts, Conny; Aguirre, Victor Silva; Ahumada, Romina; Ajgaonkar, Nikhil; Ak, N. Filiz; Alam, Shadab; Prieto, Carlos Allende; Almeida, Andres; Anders, Friedrich; Anderson, Scott F.; Andrews, Brett H.; Anguiano, Borja; Aquino-Ortiz, Erik; Aragon-Salamanca, Alfonso; Argudo-Fernandez, Maria; Ata, Metin; Aubert, Marie; Avila-Reese, Vladimir; Badenes, Carles; Barba, Rodolfo H.; Barger, Kat; Barrera-Ballesteros, Jorge K.; Beaton, Rachael L.; Beers, Timothy C.; Belfiore, Francesco; Bender, Chad F.; Bernardi, Mariangela; Bershady, Matthew A.; Beutler, Florian; Bidin, Christian Moni; Bird, Jonathan C.; Bizyaev, Dmitry; Blanc, Guillermo A.; Blanton, Michael R.; Boardman, Nicholas Fraser; Bolton, Adam S.; Boquien, Mederic; Borissova, Jura; Bovy, Jo; Brandt, W. N.; Brown, Jordan; Brownstein, Joel R.; Brusa, Marcella; Buchner, Johannes; Bundy, Kevin; Burchett, Joseph N.; Bureau, Martin; Burgasser, Adam; Cabang, Tuesday K.; Campbell, Stephanie; Cappellari, Michele; Carlberg, Joleen K.; Wanderley, Fabio Carneiro; Carrera, Ricardo; Cash, Jennifer; Chen, Yan-Ping; Chen, Wei-Huai; Cherinka, Brian; Chiappini, Cristina; Choi, Peter Doohyun; Chojnowski, S. Drew; Chung, Haeun; Clerc, Nicolas; Cohen, Roger E.; Comerford, Julia M.; Comparat, Johan; da Costa, Luiz; Covey, Kevin; Crane, Jeffrey D.; Cruz-Gonzalez, Irene; Culhane, Connor; Cunha, Katia; Dai, Y. Sophia; Damke, Guillermo; Darling, Jeremy; Davidson, James W., Jr.; Davies, Roger; Dawson, Kyle; De Lee, Nathan; Diamond-Stanic, Aleksandar M.; Cano-Diaz, Mariana; Sanchez, Helena Dominguez; Donor, John; Duckworth, Chris; Dwelly, Tom; Eisenstein, Daniel J.; Elsworth, Yvonne P.; Emsellem, Eric; Eracleous, Mike; Escoffier, Stephanie; Fan, Xiaohui; Farr, Emily; Feng, Shuai; Fernandez-Trincado, Jose G.; Feuillet, Diane; Filipp, Andreas; Fillingham, Sean P.; Frinchaboy, Peter M.; Fromenteau, Sebastien; Galbany, Lluis; Garcia, Rafael A.; Garcia-Hernandez, D. A.; Ge, Junqiang; Geisler, Doug; Gelfand, Joseph; Geron, Tobias; Gibson, Benjamin J.; Goddy, Julian; Godoy-Rivera, Diego; Grabowski, Kathleen; Green, Paul J.; Greener, Michael; Grier, Catherine J.; Griffith, Emily; Guo, Hong; Guy, Julien; Hadjara, Massinissa; Harding, Paul; Hasselquist, Sten; Hayes, Christian R.; Hearty, Fred; Hill, Lewis; Hogg, David W.; Holtzman, Jon A.; Horta, Danny; Hsieh, Bau-Ching; Hsu, Chin-Hao; Hsu, Yun-Hsin; Huber, Daniel; Huertas-Company, Marc; Hutchinson, Brian; Hwang, Ho Seong; Ibarra-Medel, Hector J.; Chitham, Jacob Ider; Ilha, Gabriele S.; Imig, Julie; Jaekle, Will; Jayasinghe, Tharindu; Ji, Xihan; Johnson, Jennifer A.; Jones, Amy; Jonsson, Henrik; Katkov, Ivan; Khalatyan, Arman; Kinemuchi, Karen; Kisku, Shobhit; Knapen, Johan H.; Kneib, Jean-Paul; Kollmeier, Juna A.; Kong, Miranda; Kounkel, Marina; Kreckel, Kathryn; Krishnarao, Dhanesh; Lacerna, Ivan; Lane, Richard R.; Langgin, Rachel; Lavender, Ramon; Law, David R.; Lazarz, Daniel; Leung, Henry W.; Leung, Ho-Hin; Lewis, Hannah M.; Li, Cheng; Li, Ran; Lian, Jianhui; Liang, Fu-Heng; Lin, Lihwai; Lin, Yen-Ting; Lin, Sicheng; Lintott, Chris; Long, Dan; Longa-Pena, Penelope; Lopez-Coba, Carlos; Lu, Shengdong; Lundgren, Britt F.; Luo, Yuanze; Mackereth, J. Ted; de la Macorra, Axel; Mahadevan, Suvrath; Majewski, Steven R.; Manchado, Arturo; Mandeville, Travis; Maraston, Claudia; Margalef-Bentabol, Berta; Masseron, Thomas; Masters, Karen L.; Mathur, Savita; McDermid, Richard M.; Mckay, Myles; Merloni, Andrea; Merrifield, Michael; Meszaros, Szabolcs; Miglio, Andrea; Di Mille, Francesco; Minniti, Dante; Minsley, Rebecca; Monachesi, Antonela; Moon, Jeongin; Mosser, Benoit; Mulchaey, John; Muna, Demitri; Munoz, Ricardo R.; Myers, Adam D.; Myers, Natalie; Nadathur, Seshadri; Nair, Preethi; Nandra, Kirpal; Neumann, Justus; Newman, Jeffrey A.; Nidever, David L.; Nikakhtar, Farnik; Nitschelm, Christian; O'Connell, Julia E.; Garma-Oehmichen, Luis; de Oliveira, Gabriel Luan Souza; Olney, Richard; Oravetz, Daniel; Ortigoza-Urdaneta, Mario; Osorio, Yeisson; Otter, Justin; Pace, Zachary J.; Padilla, Nelson; Pan, Kaike; Pan, Hsi-An; Parikh, Taniya; Parker, James; Peirani, Sebastien; Ramirez, Karla Pena; Penny, Samantha; Percival, Will J.; Perez-Fournon, Ismael; Pinsonneault, Marc; Poidevin, Frederick; Poovelil, Vijith Jacob; Price-Whelan, Adrian M.; Queiroz, Anna Barbara de Andrade; Raddick, M. Jordan; Ray, Amy; Rembold, Sandro Barboza; Riddle, Nicole; Riffel, Rogemar A.; Riffel, Rogerio; Rix, Hans-Walter; Robin, Annie C.; Rodriguez-Puebla, Aldo; Roman-Lopes, Alexandre; Roman-Zuniga, Carlos; Rose, Benjamin; Ross, Ashley J.; Rossi, Graziano; Rubin, Kate H. R.; Salvato, Mara; Sanchez, Sebastian F.; Sanchez-Gallego, Jose R.; Sanderson, Robyn; Rojas, Felipe Antonio Santana; Sarceno, Edgar; Sarmiento, Regina; Sayres, Conor; Sazonova, Elizaveta; Schaefer, Adam L.; Schiavon, Ricardo; Schlegel, David J.; Schneider, Donald P.; Schultheis, Mathias; Schwope, Axel; Serenelli, Aldo; Serna, Javier; Shao, Zhengyi; Shapiro, Griffin; Sharma, Anubhav; Shen, Yue; Shetrone, Matthew; Shu, Yiping; Simon, Joshua D.; Skrutskie, M. F.; Smethurst, Rebecca; Smith, Verne; Sobeck, Jennifer; Spoo, Taylor; Sprague, Dani; Stark, David, V; Stassun, Keivan G.; Steinmetz, Matthias; Stello, Dennis; Stone-Martinez, Alexander; Storchi-Bergmann, Thaisa; Stringfellow, Guy S.; Stutz, Amelia; Su, Yung-Chau; Taghizadeh-Popp, Manuchehr; Talbot, Michael S.; Tayar, Jamie; Telles, Eduardo; Teske, Johanna; Thakar, Ani; Theissen, Christopher; Tkachenko, Andrew; Thomas, Daniel; Tojeiro, Rita; Toledo, Hector Hernandez; Troup, Nicholas W.; Trump, Jonathan R.; Trussler, James; Turner, Jacqueline; Tuttle, Sarah; Unda-Sanzana, Eduardo; Vazquez-Mata, Jose Antonio; Valentini, Marica; Valenzuela, Octavio; Vargas-Gonzalez, Jaime; Vargas-Magana, Mariana; Alfaro, Pablo Vera; Villanova, Sandro; Vincenzo, Fiorenzo; Wake, David; Warfield, Jack T.; Washington, Jessica Diane; Weaver, Benjamin Alan; Weijmans, Anne-Marie; Weinberg, David H.; Weiss, Achim; Westfall, Kyle B.; Wild, Vivienne; Wilde, Matthew C.; Wilson, John C.; Wilson, Robert F.; Wilson, Mikayla; Wolf, Julien; Wood-Vasey, W. M.; Yan, Renbin; Zamora, Olga; Zasowski, Gail; Zhang, Kai; Zhao, Cheng; Zheng, Zheng; Zheng, Zheng; Zhu, Kai
    This paper documents the seventeenth data release (DR17) from the Sloan Digital Sky Surveys; the fifth and final release from the fourth phase (SDSS-IV). DR17 contains the complete release of the Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey, which reached its goal of surveying over 10,000 nearby galaxies. The complete release of the MaNGA Stellar Library accompanies this data, providing observations of almost 30,000 stars through the MaNGA instrument during bright time. DR17 also contains the complete release of the Apache Point Observatory Galactic Evolution Experiment 2 survey that publicly releases infrared spectra of over 650,000 stars. The main sample from the Extended Baryon Oscillation Spectroscopic Survey (eBOSS), as well as the subsurvey Time Domain Spectroscopic Survey data were fully released in DR16. New single-fiber optical spectroscopy released in DR17 is from the SPectroscipic IDentification of ERosita Survey subsurvey and the eBOSS-RM program. Along with the primary data sets, DR17 includes 25 new or updated value-added catalogs. This paper concludes the release of SDSS-IV survey data. SDSS continues into its fifth phase with observations already underway for the Milky Way Mapper, Local Volume Mapper, and Black Hole Mapper surveys.