A. Calamida
A5013725208- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Astrophysics and Star Formation Studies
- Gamma-ray bursts and supernovae
- Adaptive optics and wavefront sensing
- Astro and Planetary Science
- Astronomical Observations and Instrumentation
- CCD and CMOS Imaging Sensors
- Nuclear Physics and Applications
- Astrophysical Phenomena and Observations
- Radiation Detection and Scintillator Technologies
- Galaxies: Formation, Evolution, Phenomena
- Calibration and Measurement Techniques
- Nuclear reactor physics and engineering
- Sensor Technology and Measurement Systems
- Radiation Therapy and Dosimetry
- Optical Systems and Laser Technology
- Space Exploration and Technology
- Infrared Target Detection Methodologies
- Atomic and Subatomic Physics Research
- Pulsars and Gravitational Waves Research
- History and Developments in Astronomy
- Advanced Semiconductor Detectors and Materials
- Plasma Diagnostics and Applications
- Geophysics and Gravity Measurements
Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Frascati
2021-2024
Istituto Nazionale di Fisica Nucleare
2022-2024
National Agency for New Technologies, Energy and Sustainable Economic Development
2024
Space Telescope Science Institute
2014-2023
Kitt Peak National Observatory
2016-2019
Michigan Science Center
2013-2019
Optica
2016-2019
University of Rome Tor Vergata
2005-2018
Astronomical Observatory of Rome
2006-2017
National Institute for Astrophysics
2007-2014
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...
Pan-STARRS1 has carried out a set of distinct synoptic imaging sky surveys including the $3π$ Steradian Survey and Medium Deep in 5 bands ($grizy_{P1}$). The mean 5$σ$ point source limiting sensitivities stacked 3$π$ $grizy_{P1}$ are (23.3, 23.2, 23.1, 22.3, 21.4) respectively. upper bound on systematic uncertainty photometric calibration across is 7-12 millimag depending bandpass. astrometric using Gaia frame comes from comparison results with Gaia: standard deviation median residuals ($...
This paper describes the organization of database and catalog data products from Pan-STARRS1 $3\pi$ Steradian Survey. The are available in form an SQL-based relational MAST, Mikulski Archive for Space Telescopes at STScI. is described detail, including construction database, provenance data, schema, how tables related. Examples queries a range science goals included.
Abstract We report the first unambiguous detection and mass measurement of an isolated stellar-mass black hole (BH). used Hubble Space Telescope (HST) to carry out precise astrometry source star long-duration ( t E ≃ 270 days), high-magnification microlensing event MOA-2011-BLG-191/OGLE-2011-BLG-0462 (hereafter designated as MOA-11-191/OGLE-11-462), in direction Galactic bulge. HST imaging, conducted at eight epochs over interval 6 yr, reveals a clear relativistic astrometric deflection...
Gravitational deflection of starlight around the Sun during 1919 total solar eclipse provided measurements that confirmed Einstein's general theory relativity. We have used Hubble Space Telescope to measure analogous process astrometric microlensing caused by a nearby star, white dwarf Stein 2051 B. As B passed closely in front background star's position was deflected. Measurement this at multiple epochs allowed us determine mass -- sixth nearest as 0.675 +/- 0.051 masses. This determination...
Despite the huge amount of photometric and spectroscopic efforts targetting Galactic bulge over past few years, its age distribution remains controversial owing to both complexity determining individual stars difficult observing conditions. Taking advantage recent release very deep, proper-motion-cleaned colour--magnitude diagrams (CMDs) four low reddening windows obtained with Hubble Space Telescope (HST), we used CMD-fitting technique calculate star formation history (SFH) at -2deg > b...
The determination of the age bulge has led to two contradictory results. On one side, color–magnitude diagrams in different fields seem indicate a uniformly old (>10 Gyr) population. other individual ages derived from dwarfs observed through microlensing events wide spread, ~2 ~13 Gyr. Because is now recognised as being mainly boxy peanut-shaped bar, it suggested that disk stars are its main constituents, and therefore also with significantly younger than 10 Other arguments point out cannot...
A large fraction of Type Ia supernova (SN Ia) observations over the next decade will be in near-infrared (NIR), at wavelengths beyond reach current standard light-curve model for SN cosmology, SALT3 ($\sim 2800$--8700$A$ central filter wavelength). To harness this new sample and reduce future standardization systematic uncertainties, we train NIR (SALT3-NIR) up to 2 $\mu$m with open-source model-training software SALTShaker, which can easily accommodate observations. Using simulated data...
In November 2019, the nearby single, isolated DQ-type white dwarf LAWD 37 (WD 1142-645) aligned closely with a distant background source and caused an astrometric microlensing event. Leveraging astrometry from \Gaia{} followup data \textit{Hubble Space Telescope} we measure deflection of obtain gravitational mass for LAWD~37. The main challenge this analysis is in extracting lensing signal faint whilst it buried wings LAWD~37's point spread function. Removal 37's function induces significant...
We present a new method to estimate the absolute ages of stellar systems. This is based on difference in magnitude between main sequence turn-off (MSTO) and well defined knee located along lower (MSK). feature caused by collisionally induced absorption molecular hydrogen it can be easily identified near-infrared (NIR) optical-NIR color-magnitude diagrams took advantage deep accurate NIR images collected with Multi-Conjugate Adaptive Optics Demonstrator temporarily available Very Large...
ABSTRACT Globular Clusters (GCs) in the Milky Way are primary laboratories for establishing ages of oldest stellar populations and measuring color–magnitude relation stars. In infrared (IR) diagrams (CMDs), main sequence (MS) exhibits a “kink” due to opacity effects M dwarfs such that lower mass cooler become bluer IR color baseline. This diagnostic offers new opportunity model GC CMDs reduce uncertainties on cluster properties (e.g., their derived ages). this context, we analyzed Hubble...
We present a new complete Near-Infrared (NIR, $JHK_s$) census of RR Lyrae stars (RRLs) in the globular $\omega$ Cen (NGC 5139). collected 15,472 $JHK_s$ images with 4-8m class telescopes over 15 years (2000-2015) covering sky area around cluster center 60x34 arcmin$^2$. These provided calibrated photometry for 182 out 198 RRL candidates ten to sixty measurements per band. also provide homogeneous estimates photometric amplitude 180 ($J$), 176 ($H$) and 174 ($K_s$) RRLs. data were...
We have derived the Galactic bulge initial mass function (IMF) of Sagittarius Window Eclipsing Extrasolar Planet Search field in range 0.15 1.0, using deep photometry collected with Advanced Camera for Surveys on Hubble Space Telescope. Observations at several epochs, spread over 9 years, allowed us to separate disk and stars down very faint magnitudes, 26 mag, a proper-motion accuracy better than 0.5 mas yr−1 (20 km s−1). This determine IMF pure component uncontaminated by this...
New accurate and homogeneous optical UBVRI photometry has been obtained for variable stars in the Galactic globular $\omega$ Cen (NGC 5139). We secured 8202 CCD images covering a time interval of 24 years sky area 84x48 arcmin. The current data were complemented with available literature provided new, pulsation parameters (mean magnitudes, luminosity amplitudes,periods) 187 candidate RR Lyrae (RRLs). Among them we have 101 RRc (first overtone), 85 RRab (fundamental) single RRd (double-mode)...
Eridanus II (EriII) is an ultra-faint dwarf (UFD) galaxy (M_V=-7.1) located at a distance close to the Milky Way virial radius. Early shallow color-magnitude diagrams (CMD) indicated that it possibly hosted intermediate-age or even young stellar population, which unusual for of this mass. In paper, we present new ACS/HST CMDs reaching oldest main sequence turnoff with excellent photometric precision, and derive precise star formation history (SFH) through CMD-fitting. This SFH shows bulk...
We present a new photometric calibration of the WFC3-UVIS and WFC3-IR detectors based on observations collected from 2009 to 2020 for four white dwarfs, namely GRW+70~5824, GD~153, GD~71, G191B2B, G-type star, P330E. These calibrations include recent updates Hubble Space Telescope primary standard dwarf models reference flux Vega. Time-dependent inverse sensitivities two chips, UVIS1 UVIS2, were calculated all 42 full-frame filters, after accounting temporal changes in observed count rates...
We present new Near-Infrared (J,K) magnitudes for 114 RR Lyrae stars in the globular cluster Omega Cen (NGC 5139) which we combine with data from literature to construct a sample of 180 J and K mean on common photometric system. This is presently largest such any stellar also updated predictions J,K-band Period-Luminosity relations both fundamental first-overtone stars, based synthetic horizontal branch models metal abundance ranging Z=0.0001 Z=0.004. By adopting variables measured...
We present a new calibration of the Strömgren metallicity index m1 using red giant (RG) stars in four globular clusters (GCs: M92, M13, NGC 1851, 47 Tuc) with ranging from -2.2 to -0.7, marginally affected by reddening [E(B - V) ≤ 0.04] and accurate (u, v, b, y) photometry. The main difference between metallicity-index-color (MIC) relations similar available literature is that we have adopted u y v colors instead b y. These stronger sensitivity effective temperature, MIC show linear slope....
We present new intermediate-band Strömgren photometry based on more than 300 u, v, b, y images of the Galactic globular cluster ω Cen. Optical data were supplemented with multiband near-infrared (NIR) (350 J, H, Ks images). The final optical–NIR catalog covers a region 20 × arcmin squared across center. use different color–color planes together proper-motion available in literature to identify candidate red-giant (RG) stars. By adopting metallicity indices, we estimate photometric for ≈4000...
UV observations of some massive globular clusters have revealed a significant population stars hotter and fainter than the hot end horizontal branch (HB), so-called blue hook stars. This feature might be explained either by late flasher scenario where experience helium flash while on white dwarf cooling curve or progeny helium-enriched sub-population postulated to exist in clusters. Previous spectroscopic analyses omega Cen NGC 2808 support scenario, but contain much less expected predicted...
We present new empirical estimates of the Delta V_HB_bump parameter for 15 Galactic globular clusters (GGCs) using accurate and homogeneous ground-based optical data. Together with similar evaluations available in literature, we ended up a sample 62 GGCs covering very broad range metal content (-2.16<=[M/H]<=-0.58 dex). Adopting metallicity scale provided either by Kraft & Ivans (2004) or Carretta et al. (2009), found that observed parameters are larger than predicted. In metal-poor regime...
Abstract We have established a network of 19 faint (16.5 mag < V mag) northern and equatorial DA white dwarfs (WDs) as spectrophotometric standards for present future wide-field observatories. Our analysis infers spectral energy distribution (SED) models the stars that are tied to three CALSPEC primary standards. SED consistent with panchromatic Hubble Space Telescope photometry better than 1%. The excellent agreement between observations validates use non-LTE WD atmospheres extinguished...
We present precise optical and near-infrared ground-based photometry of two Globular Clusters (GCs): Omega Cen 47 Tuc. These photometric catalogs are unbiased in the Red Giant Branch (RGB) region close to tip. provide new estimates RGB tip (TRGB) magnitudes--m_I(TRGB)=9.84+/-0.05, Cen; m_I(TRGB)=9.46+/-0.06, Tuc--and use these determine relative distances GCs. find that distance ratios based on different calibrations TRGB, RR Lyrae stars kinematic agree with each other within one sigma....
We report on the first results from a large-scale observing campaign aiming to use astrometric microlensing detect and place limits mass of single objects, including stellar remnants. used Hubble Space Telescope monitor stars near Galactic Center for 3 years, we measured brightness positions $\sim$2 million at each epoch. In addition this, monitored same pointings using VIMOS imager Very Large Telescope. The include several bright events observed ground by OGLE collaboration. this paper,...