F. J. Castander
A5023412378- Galaxies: Formation, Evolution, Phenomena
- Astronomy and Astrophysical Research
- Gamma-ray bursts and supernovae
- Stellar, planetary, and galactic studies
- Cosmology and Gravitation Theories
- Astronomical Observations and Instrumentation
- Adaptive optics and wavefront sensing
- Astrophysics and Cosmic Phenomena
- CCD and CMOS Imaging Sensors
- Astrophysical Phenomena and Observations
- Dark Matter and Cosmic Phenomena
- Remote Sensing in Agriculture
- Scientific Research and Discoveries
- Radio Astronomy Observations and Technology
- Pulsars and Gravitational Waves Research
- Astrophysics and Star Formation Studies
- History and Developments in Astronomy
- Gaussian Processes and Bayesian Inference
- Impact of Light on Environment and Health
- Calibration and Measurement Techniques
- Astro and Planetary Science
- Advanced Vision and Imaging
- Geophysics and Gravity Measurements
- Advanced Image Processing Techniques
- Statistical and numerical algorithms
Institute of Space Sciences
2016-2025
Institut d'Estudis Espacials de Catalunya
2016-2025
Universitat Politècnica de Catalunya
2025
European Space Astronomy Centre
2024
Institute for High Energy Physics
2008-2024
Institute of Space Science - INFLPR Subsidiary
2023-2024
Texas A&M University
2024
University College London
2024
University of Copenhagen
2024
Flatiron Health (United States)
2024
The Sloan Digital Sky Survey (SDSS) will provide the data to support detailed investigations of distribution luminous and nonluminous matter in universe: a photometrically astrometrically calibrated digital imaging survey π sr above about Galactic latitude 30° five broad optical bands depth g' ∼ 23 mag, spectroscopic approximately 106 brightest galaxies 105 quasars found photometric object catalog produced by survey. This paper summarizes observational parameters products SDSS serves as an...
This paper describes the Seventh Data Release of Sloan Digital Sky Survey (SDSS), marking completion original goals SDSS and end phase known as SDSS-II. It includes 11,663 deg2 imaging data, with most ∼2000 increment over previous data release lying in regions low Galactic latitude. The catalog contains five-band photometry for 357 million distinct objects. survey also repeat on a 120° long, 25 wide stripe along celestial equator Southern Cap, some covered by many 90 individual runs. We...
We measure cosmological parameters using the three-dimensional power spectrum $P(k)$ from over 200 000 galaxies in Sloan Digital Sky Survey (SDSS) combination with Wilkinson Microwave Anisotropy Probe (WMAP) and other data. Our results are consistent a ``vanilla'' flat adiabatic cold dark matter model constant without tilt ${(n}_{s}=1),$ running tilt, tensor modes, or massive neutrinos. Adding SDSS information more than halves WMAP-only error bars on some parameters, tightening...
We present the large-scale correlation function measured from a spectroscopic sample of 46,748 luminous red galaxies Sloan Digital Sky Survey. The survey region covers 0.72 h-3 Gpc3 over 3816 deg2 and 0.16 < z 0.47, making it best yet for study structure. find well-detected peak in at 100 h-1 Mpc separation that is an excellent match to predicted shape location imprint recombination-epoch acoustic oscillations on low-redshift clustering matter. This detection demonstrates linear growth...
The Sloan Digital Sky Survey (SDSS) is an imaging and spectroscopic survey that will eventually cover approximately one-quarter of the celestial sphere collect spectra ≈106 galaxies, 100,000 quasars, 30,000 stars, serendipity targets. In 2001 June, SDSS released to general astronomical community its early data release, roughly 462 deg2 including almost 14 million detected objects 54,008 follow-up spectra. were collected in drift-scan mode five bandpasses (u, g, r, i, z); our 95% completeness...
We develop a new method to constrain the star formation histories, dust attenuation and stellar masses of galaxies. It is based on two absorption-line indices, 4000-Å break strength Balmer index HδA. Together, these indices allow us mean ages galaxies fractional mass formed in bursts over past few Gyr. A comparison with broad-band photometry then yields estimates mass. generate large library Monte Carlo realizations different including starbursts varying range metallicities. use this median...
We have created a variety of composite quasar spectra using homogeneous data set over 2200 from the Sloan Digital Sky Survey (SDSS). The sample spans redshift range 0.044 ≤ z 4.789 and an absolute r' magnitude -18.0 to -26.5. input cover observed wavelength 3800–9200 Å at resolution 1800. median covers rest-wavelength 800 8555 reaches peak signal-to-noise ratio 300 per 1 element in rest frame. identified 80 emission-line features spectrum. Emission-line shifts relative nominal laboratory...
We measure the large-scale real-space power spectrum P(k) using a sample of 205,443 galaxies from Sloan Digital Sky Survey, covering 2417 square degrees with mean redshift z~0.1. employ matrix-based method pseudo-Karhunen-Loeve eigenmodes, producing uncorrelated minimum-variance measurements in 22 k-bands both clustering and its anisotropy due to redshift-space distortions, narrow well-behaved window functions range 0.02 h/Mpc < k 0.3h/Mpc. pay particular attention modeling, quantifying...
We study the optical colors of 147,920 galaxies brighter than g* = 21, observed in five bands by Sloan Digital Sky Survey (SDSS) over ∼100 deg2 high Galactic latitude sky along celestial equator. The distribution g*-r* versus u*-g* color-color diagram is strongly bimodal, with an optimal color separator u*-r* 2.22. use visual morphology and spectral classification subsamples 287 500 galaxies, respectively, to show that two peaks correspond roughly early- (E, S0, Sa) late-type (Sb, Sc, Irr)...
We measure the large-scale real-space power spectrum $P(k)$ using luminous red galaxies (LRGs) in Sloan Digital Sky Survey (SDSS) and use this measurement to sharpen constraints on cosmological parameters from Wilkinson Microwave Anisotropy Probe (WMAP). employ a matrix-based estimation method Pseudo-Karhunen-Lo\`eve eigenmodes, producing uncorrelated minimum-variance measurements 20 $k$-bands of both clustering its anisotropy due redshift-space distortions, with narrow well-behaved window...
DESI (Dark Energy Spectroscopic Instrument) is a Stage IV ground-based dark energy experiment that will study baryon acoustic oscillations (BAO) and the growth of structure through redshift-space distortions with wide-area galaxy quasar redshift survey. To trace underlying matter distribution, spectroscopic targets be selected in four classes from imaging data. We measure luminous red galaxies up to $z=1.0$. probe Universe out even higher redshift, target bright [O II] emission line $z=1.7$....
Abstract The DESI Legacy Imaging Surveys ( http://legacysurvey.org/ ) are a combination of three public projects (the Dark Energy Camera Survey, the Beijing–Arizona Sky and Mayall z -band Survey) that will jointly image ≈14,000 deg 2 extragalactic sky visible from northern hemisphere in optical bands g , r using telescopes at Kitt Peak National Observatory Cerro Tololo Inter-American Observatory. combined survey footprint is split into two contiguous areas by Galactic plane. imaging...
This paper describes the Sixth Data Release of Sloan Digital Sky Survey. With this data release, imaging northern Galactic cap is now complete. The survey contains images and parameters roughly 287 million objects over 9583 deg2, including scans a large range latitudes longitudes. also includes 1.27 spectra stars, galaxies, quasars, blank sky (for subtraction) selected 7425 deg2. release much more stellar spectroscopy than was available in previous releases detailed estimates temperatures,...
We present cosmological results from a combined analysis of galaxy clustering and weak gravitational lensing, using 1321 deg$^2$ $griz$ imaging data the first year Dark Energy Survey (DES Y1). combine three two-point functions: (i) cosmic shear correlation function 26 million source galaxies in four redshift bins, (ii) angular autocorrelation 650,000 luminous red five (iii) galaxy-shear cross-correlation positions shears. To demonstrate robustness these results, we use independent pairs...
The Sloan Digital Sky Survey (SDSS) has validated and made publicly available its Second Data Release. This data release consists of 3324 deg2 five-band (ugriz) imaging with photometry for over 88 million unique objects, 367,360 spectra galaxies, quasars, stars, calibrating blank sky patches selected 2627 this area, tables measured parameters from these data. reach a depth r ≈ 22.2 (95% completeness limit point sources) are photometrically astrometrically calibrated to 2% rms 100 mas per...
We present the design and performance of multi-object fiber spectrographs for Sloan Digital Sky Survey (SDSS) their upgrade Baryon Oscillation Spectroscopic (BOSS). Originally commissioned in Fall 1999 on 2.5-m aperture Telescope at Apache Point Observatory, produced more than 1.5 million spectra SDSS SDSS-II surveys, enabling a wide variety Galactic extra-galactic science including first observation baryon acoustic oscillations 2005. The were upgraded 2009 are currently use BOSS, flagship...
We describe the target selection and resulting properties of a spectroscopic sample luminous red galaxies (LRGs) from imaging data Sloan Digital Sky Survey (SDSS). These are selected on basis color magnitude to yield intrinsically that extends fainter farther than main flux-limited portion SDSS galaxy sample. The is designed impose passively evolving luminosity rest-frame cut redshift 0.38. Additional, yet more included ∼0.5. Approximately 12 these per square degree targeted for...
The Sloan Digital Sky Survey has validated and made publicly available its First Data Release. This consists of 2099 square degrees five-band (u, g, r, i, z) imaging data, 186,240 spectra galaxies, quasars, stars calibrating blank sky patches selected over 1360 this area, tables measured parameters from these data. data go to a depth r ~ 22.6 are photometrically astrometrically calibrated 2% rms 100 milli-arcsec per coordinate, respectively. cover the range 3800--9200 A, with resolution...
We present UV, optical, and NIR photometry of the first electromagnetic counterpart to a gravitational wave source from Advanced LIGO/Virgo, binary neutron star merger GW170817. Our data set extends discovery optical at $0.47$ days $18.5$ post-merger, includes observations with Dark Energy Camera (DECam), Gemini-South/FLAMINGOS-2 (GS/F2), {\it Hubble Space Telescope} ({\it HST}). The spectral energy distribution (SED) inferred this $0.6$ is well described by blackbody model $T\approx 8300$...
We present the first cosmology results from large-scale structure in Dark Energy Survey (DES) spanning 5000 deg$^2$. perform an analysis combining three two-point correlation functions (3$\times$2pt): (i) cosmic shear using 100 million source galaxies, (ii) galaxy clustering, and (iii) cross-correlation of with lens positions. The was designed to mitigate confirmation or observer bias; we describe specific changes made sample following unblinding results. model data within flat $\Lambda$CDM...
This overview paper describes the legacy prospect and discovery potential of Dark Energy Survey (DES) beyond cosmological studies, illustrating it with examples from DES early data.DES is using a wide-field camera (DECam) on 4 m Blanco Telescope in Chile to image 5000 sq deg sky five filters (grizY).
We present in this paper a detailed analysis of the effect environment on star formation activity galaxies within Early Data Release (EDR) Sloan Digital Sky Survey (SDSS). have used Hα emission line to derive rate (SFR) for each galaxy volume-limited sample 8598 with 0.05 ≤ z 0.095 and M(r*) -20.45. find that SFR is strongly correlated local (projected) density, thus we here density-SFR relation analogous density-morphology relation. The density seen three ways. First, overall distribution...
This paper describes the Third Data Release of Sloan Digital Sky Survey (SDSS). release, containing data taken up through 2003 June, includes imaging in five bands over 5282 deg2, photometric and astrometric catalogs 141 million objects detected these data, spectra 528,640 selected 4188 deg2. The pipelines analyzing both images spectroscopy are unchanged from those used our Second Release.