This project consists of two parts, each differentiated but both complementary: morphology and dynamics. Detailed study of the morphology of the Milky Way pretends to provide a data base for the stellar distribution in the most remote and heavily obscured regions of our Galaxy, through the development of semiempirical models based on the information in these catalogues. Kinematic and dynamical analysis, on the other hand, aims to aid our understanding of the origin of these observed features.
Our group has used a combination of its own data (which will include in the future spectroscopical observations with GRANTECAN/EMIR) and public-domain catalogues either in photometry (DENIS, 2MASS, UKIDSS, VISTA, SDSS) or spectroscopy (SDSS-APOGEE in near infrared, LAMOST). We have gathered detailed information on the stellar distribution of the dominant populations over a wide area of sky containing different structural components: the triaxial bulge, the long bar, the disc, the spiral arms, etc. The components of gas and dust are also a matter of study in infrared, or in microwave (analyses of Galactic contamination over the cosmic microwave background radiation, for instance with WMAP or PLANCK). Our research team has also become part of the Spanish node of Gaia with the idea of orientating part of our work towards the scientific exploitation of this mission, particularly with regard to the identification and study of large scale stellar populations in the Galaxy.
- Milky Way's disk much larger than previously thought. See press release of IAC: http://www.iac.es/divulgacion.php?op1=16&id=1385&lang=en
Diagonal Ridge Pattern of Different Age Populations Found in Gaia-DR2 with LAMOST Main-sequence Turnoff and OB-type Stars
We revisit the diagonal ridge feature (diagonal distributions in the R, vφ plane) found in Gaia and present a timing analysis for it between Galactocentric distances of R = 7.5 and 12 kpc, using main-sequence turnoff and OB stars selected from the LAMOST Galactic spectroscopic surveys. We recover the ridge pattern in the R-vφ plane color coded byWang, H. -F. et al.
Gaia-DR2 extended kinematical maps. III. Rotation curves analysis, dark matter, and MOND tests
Context. Recent statistical deconvolution methods have produced extended kinematical maps in a range of heliocentric distances that are a factor of two to three larger than those analysed in Gaia Collaboration (2018, A&A, 616, A11) based on the same data. Aims: In this paper, we use such maps to derive the rotation curve both in the Galactic planeChrobáková, Ž. et al.
The Sloan Digital Sky Survey Quasar Catalog: Sixteenth Data Release
We present the final Sloan Digital Sky Survey IV (SDSS-IV) quasar catalog from Data Release 16 of the extended Baryon Oscillation Spectroscopic Survey (eBOSS). This catalog comprises the largest selection of spectroscopically confirmed quasars to date. The full catalog includes two subcatalogs (the current versions are DR16Q_v4 and DR16Q_SupersetLyke, Brad W. et al.
Mapping the Galactic Disk with the LAMOST and Gaia Red Clump Sample. VI. Evidence for the Long-lived Nonsteady Warp of Nongravitational Scenarios
By combining LAMOST DR4 and Gaia DR2 common red clump stars with age and proper motion, we analyze the amplitude evolution of the stellar warp independently of any assumption with a simple model. The greatest height of the warp disk increases with galactocentric distance in different populations and is dependent on age: the younger stellarWang, H. -F. et al.
Structure of the outer Galactic disc with Gaia DR2
Context. The structure of outer disc of our Galaxy is still not well described, and many features need to be better understood. The second Gaia data release (DR2) provides data in unprecedented quality that can be analysed to shed some light on the outermost parts of the Milky Way. Aims: We calculate the stellar density using star counts obtainedChrobáková, Ž. et al.
Peculiar emission line spectra of core extremely red BOSS quasars at z̃2-3: orientation and/or evolution?
Context. Core extremely red quasars (core ERQ) have been proposed to represent an intermediate evolutionary phase in which a heavily obscured quasar blows out the circumnuclear interstellar medium with very energetic outflows before it becomes an optical quasar. Aims: We investigate whether the properties of core ERQ fit the AGN orientation-basedVillar Martín, M. et al.
Gaia-DR2 extended kinematical maps. II. Dynamics in the Galactic disk explaining radial and vertical velocities
Context. In our Paper I, by using statistical deconvolution methods, extended kinematics maps of Gaia-DR2 data have been produced in a range of heliocentric distances that are a factor of two to three larger than those analyzed previously by the Gaia Collaboration with the same data. It added the range of Galactocentric distances between 13 kpc andLópez-Corredoira, M. et al.
Searching for optical companions to four binary millisecond pulsars with the Gran Telescopio Canarias
We report on multiband photometric observations of four binary millisecond pulsars with the Gran Telescopio Canarias. The observations led to detection of binary companions to PSRs J1630+3734, J1741+1351, and J2042+0246 in the Sloan g', r', and i' bands. Their magnitudes in the r' band are ≈24.4, 24.4, and 24.0, respectively. We also set a 3σ upperKirichenko, A. Yu et al.
Mapping the Galactic disc with the LAMOST and Gaia red clump sample: II. 3D asymmetrical kinematics of mono-age populations in the disc between 6-14 kpc
We perform analysis of the 3D kinematics of Milky Way disc stars in mono-age populations. We focus on stars between Galactocentric distances of R = 6 and 14 kpc, selected from the combined LAMOST Data Release 4 (DR4) red clump giant stars and Gaia DR2 proper motion catalogue. We confirm the 3D asymmetrical motions of recent works and provide timeWang, H. -F. et al.
Mapping the Galactic Disk with the LAMOST and Gaia Red Clump Sample. III. A New Velocity Substructure and Time Stamps of the Galactic Disk Asymmetry in the Disk between 12 and 15 kpc
We investigate the three-dimensional asymmetrical kinematics and present time stamps of the Milky Way disk between Galactocentric distances of R = 12 and 15 kpc, using red clump stars selected from the LAMOST Galactic survey, also with proper motion measurements provided by the Gaia DR2. We discover velocity substructure above the Galactic planeWang, Hai-Feng et al.
Stars and brown dwarfs in the σ Orionis cluster. IV. IDS/INT and OSIRIS/GTC spectroscopy and Gaia DR2 astrometry
Context. Only a few open clusters are as important for the study of stellar and substellar objects, and their formation and evolution, as the young σ Orionis cluster. However, a complete spectroscopic characterisation of its whole stellar population is still missing. Aims: We filled most of that gap with a large spectroscopic and astrometric surveyCaballero, J. A. et al.
The Vanishing and Appearing Sources during a Century of Observations Project. I. USNO Objects Missing in Modern Sky Surveys and Follow-up Observations of a “Missing Star”
In this paper we report the current status of a new research program. The primary goal of the “Vanishing and Appearing Sources during a Century of Observations” project is to search for vanishing and appearing sources using existing survey data to find examples of exceptional astrophysical transients. The implications of finding such objects extendVillarroel, B. et al.
Optical validation and characterization of Planck PSZ2 sources at the Canary Islands observatories. I. First year of LP15 observations
Aims: The second catalogue of Planck Sunyaev-Zeldovich (SZ) sources, hereafter PSZ2, is the largest sample of galaxy clusters selected through their SZ signature in the full sky. At the time of publication, 21% of these objects had no known counterpart at other wavelengths. Using telescopes at the Canary Island observatories, we conducted the longStreblyanska, A. et al.
Distribution of red clump stars does not support the X-shaped Galactic bulge
Context. Claims of an X-shaped Galactic bulge were based on the assumption of red clump stars as standard candles in some lines of sight crossing the off-plane bulge. However, some doubts have been cast on whether the two peaks in star counts along the line of sight really represent a double peak in the density distribution, or whether there isLópez-Corredoira, M. et al.
QSO2 outflow characterization using data obtained with OSIRIS at the Gran Telescopio Canarias
Context. Ionized outflows are ubiquitous in non-radio-loud obscured quasars (QSO2s) at different redshifts. However, the actual size of the outflows and their efficiency for gas ejection and star formation truncation are controversial. Large-scale (exceeding several kiloparsec) extended radio structures might be necessary to identify (even toBellocchi, Enrica et al.
Mass functions, luminosity functions, and completeness measurements from clustering redshifts
This paper presents stellar mass functions and i-band luminosity functions for Sloan Digital Sky Survey (SDSS) galaxies with i < 21 using clustering redshifts. From these measurements, we also compute targeting completeness measurements for the Baryon Oscillation Spectroscopic Survey (BOSS). Clustering redshifts is a method of obtaining theBates, D. J. et al.
The new 4-m robotic telescope
We present a project to build a 4-m-diameter telescope (New Robotic Telescope [NRT]) with fully robotic operation. The telescope will be sited at the Observatory of Roque de los Muchachos in the island of La Palma (Spain). When it enters into operation in 5 years' time, it will be likely the largest robotic telescope in the world. This, inGutiérrez, C. M. et al.
The ultracool helium-atmosphere white dwarf companion of PSR J0740+6620?
We report detection of the likely companion of the binary millisecond pulsar (MSP) J0740+6620 with the Gran Telescopio Canarias in the r' and i' bands. The position of the detected starlike source coincides with the pulsar coordinates within the 1σ uncertainty of ≈0.2 arcsec. Its magnitudes are r' = 26.51 ± 0.17 and i' = 25.49 ± 0.15. Comparing theBeronya, D. M. et al.
Nonaxisymmetric models of galaxy velocity maps
Galaxy velocity mapsoften show the typical pattern of a rotating disk, consistent with the dynamical model where emitters rotate in circular orbits around the galactic center. The simplest template used to fit these maps consists in the rotating disk model (RDM) where the amplitude of circular velocities is fixed by the observed velocity profileSylos Labini, F. et al.
Gaia-DR2 extended kinematical maps . I. Method and application
Context. The Gaia Collaboration has used Gaia-DR2 sources with six-dimensional (6D) phase space information to derive kinematical maps within 5 kpc of the Sun, which is a reachable range for stars with relative error in distance lower than 20%. Aims: Here we aim to extend the range of distances by a factor of two to three, thus adding the range ofLópez-Corredoira, M. et al.