A5088492665- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Astrophysics and Star Formation Studies
- Astro and Planetary Science
- Galaxies: Formation, Evolution, Phenomena
- Gamma-ray bursts and supernovae
- Astronomical Observations and Instrumentation
- Astrophysical Phenomena and Observations
- Adaptive optics and wavefront sensing
- Astronomical and nuclear sciences
- History and Developments in Astronomy
- Calibration and Measurement Techniques
- Pulsars and Gravitational Waves Research
- Astrophysics and Cosmic Phenomena
- Scientific Research and Discoveries
- Radio Astronomy Observations and Technology
- Relativity and Gravitational Theory
- High-pressure geophysics and materials
- Solar and Space Plasma Dynamics
- Particle Detector Development and Performance
- SAS software applications and methods
- Classical Antiquity Studies
- Computational Physics and Python Applications
- Advanced Statistical Methods and Models
- Advanced Frequency and Time Standards
Osservatorio di Astrofisica e Scienza dello Spazio
2018-2024
National Institute for Astrophysics
2013-2024
Istituto di Astrofisica Spaziale e Fisica Cosmica di Bologna
2020-2021
Oxfam
2021
John Wiley & Sons (United States)
2021
Hudson Institute
2021
John Wiley & Sons (United Kingdom)
2021
Astronomical Observatory of Capodimonte
2005-2020
Osservatorio astronomico di Bologna
2012-2018
Thüringer Landessternwarte Tautenburg
2007-2012
Abstract Gamma-ray bursts (GRBs) are classified into long and short events. Long GRBs (LGRBs) associated with the end states of very massive stars, while (SGRBs) linked to merger compact objects. GRB 200826A was a peculiar event, because by definition it an SGRB, rest-frame duration ∼0.5 s. However, this event energetic soft, which is consistent LGRBs. The relatively low redshift ( z = 0.7486) motivated comprehensive, multiwavelength follow-up campaign characterize its host, search for...
The reionization of the Universe is one most important topics present day astrophysical research. plausible candidates for process are star-forming galaxies, which according to predictions majority theoretical and semi-analytical models should dominate HI ionizing background at z~3. We aim measuring Lyman continuum escape fraction, key parameters compute contribution galaxies UV background. have used ultra-deep U-band imaging (U=30.2mag 1sigma) by LBC/LBT in CANDELS/GOODS-North field, as...
HD3167 is a bright (V=8.9 mag) K0V star observed by the NASA's K2 space mission during its Campaign 8. It has been recently found to host two small transiting planets, namely, HD3167b, an ultra short period (0.96 d) super-Earth, and HD3167c, mini-Neptune on relatively long-period orbit (29.85 d). Here we present intensive radial velocity follow-up of performed with FIES@NOT, HARPS@ESO-3.6m, HARPS-N@TNG spectrographs. We revise system parameters determine radii, masses, densities planets...
Finding the sources responsible for hydrogen reionization is one of most pressing issues in cosmology. Bright QSOs are known to ionize their surrounding neighborhood, but they too few ensure required HI ionizing background. A significant contribution by faint AGNs, however, could solve problem, as recently advocated on basis a relatively large space density active nuclei at z>4. We have carried out an exploratory spectroscopic program measure emission 16 AGNs spanning broad U-I color...
Relics of ancient accretion events experienced by the Milky Way are predominantly located within stellar halo our Galaxy. However, debris from different objects display overlapping distributions in dynamical spaces, making it extremely challenging to properly disentangle their contribution build-up To shed light on this chaotic context, we initiated a program aimed at homogeneous chemical tagging local Way, focusing component retrograde motion, since is expected host large fraction stars...
Context.A severe problem for research in star-formation is that the masses of young stars are almost always estimated from evolutionary tracks alone. Since published by different groups differ, it often only possible to give a rough estimate stars. It thus crucial test and calibrate tracks. Up now, few tests could be carried out. However, now with VLTI set constrains on determining many binary precisely.
We present a new observational campaign, DWARF, aimed at detection of circumbinary extrasolar planets using the timing minima low-mass eclipsing binaries. The observations will be performed within an extensive network relatively small to medium-size telescopes with apertures ~20-200 cm. starting sample objects monitored contains (i) binaries M and K components, (ii) short-period sdB or sdO component, (iii) post-common-envelope systems containing WD, which enable determine high precision....
We report the discovery of most distant radio galaxy to date, TGSS1530 at a redshift $z=5.72$ close presumed end Epoch Reionisation. The was selected from TGSS ADR1 survey 150 MHz for having an ultra-steep spectral index, $\alpha^{\textrm{150 MHz}}_{\textrm{1.4 GHz}} = -1.4$ and compact morphology obtained using VLA imaging 1.4 GHz. No optical or infrared counterparts it were found in publicly available sky surveys. Follow-up spectroscopy position GMOS on Gemini North revealed presence...
We report the discovery from K2 of a transiting planet in an 18.25-d, eccentric (0.19$\pm$ 0.04) orbit around K2-99, 11th magnitude subgiant Virgo. confirm planetary nature companion with radial velocities, and determine that star is metal-rich ([Fe/H] = 0.20$\pm$0.05) subgiant, mass $1.60^{+0.14}_{-0.10}~M_\odot$ radius $3.1\pm 0.1~R_\odot$. The has $0.97\pm0.09~M_{\rm Jup}$ $1.29\pm0.05~R_{\rm Jup}$. A measured systemic acceleration $-2.12\pm0.04~{\rm m s^{-1} d^{-1}}$ offers compelling...
We present the discovery of three small planets transiting K2-136 (LP 358 348, EPIC 247589423), a late K dwarf in Hyades. The have orbital periods $7.9757 \pm 0.0011$, $17.30681^{+0.00034}_{-0.00036}$, and $25.5715^{+0.0038}_{-0.0040}$ days, radii $1.05 0.16$, $3.14 0.36$, $1.55^{+0.24}_{-0.21}$ $R_\oplus$, respectively. With an age 600-800 Myr, these are some smallest youngest known. Due to relatively bright (J=9.1) host star, compelling targets for future characterization via radial...
Identifying black holes is essential for our understanding of the development stars and can reveal novel principles physics. Gravitational microlensing provides an exceptional opportunity to examine undetectable population in Milky Way. In particular, long-lasting events are likely be associated with massive lenses, including holes. We present analysis Gaia18ajz event reported by Gaia Science Alerts system. a long-timescale exhibiting features indicative annual parallax effect. Our objective...
ABSTRACT We report the discovery of K2-98b (EPIC 211391664b), a transiting Neptune-size planet monitored by K2 mission during its Campaign 5. combine time-series data with ground-based photometric and spectroscopic follow-up observations to confirm planetary nature object derive mass, radius, orbital parameters. is warm Neptune-like in 10 day orbit around V = 12.2 mag F-type star M ⋆ 1.074 ± 0.042 ⊙ , R <?CDATA ${1.311}_{-0.048}^{+0.083}$?> age ${5.2}_{-1.0}^{+1.2}\,\mathrm{Gyr}$?> . mass...
We report the LBT/MODS1 spectroscopic confirmation of two images faint Lyα emitters at z = 6.4 behind Frontier Fields galaxy cluster MACSJ0717.5+3745. A wide range lens models suggests that are highly magnified, with a strong lower limit μ > 5. These faintest 6 candidates spectroscopically confirmed to date. may also be multiple same source as supported by their similar intrinsic properties, but inconclusive regarding this interpretation. To cautious, we derive physical properties each image...
Abstract We report the characterization and independent detection of K2-60b, as well K2-107b, two transiting hot gaseous planets from K2 space mission. confirm planetary nature systems determine their fundamental parameters combining time-series data with FIES@NOT HARPS-N@TNG spectroscopic observations. K2-60b has a radius 0.683 ± 0.037 R Jup mass 0.426 M orbits G4 V star an orbital period 3.00267 0.00006 days. K2-107b 1.44 0.15 0.84 0.08 F9 IV every 3.31392 0.00002 is among few at edge...
We present new photometry of the dwarf irregular galaxy DDO 68, one most metal-poor and least massive dwarfs, located in Lynx-Cancer Void. The images were acquired with Large Binocular Telescope g r passbands, show unequivocally that 68 has previously unknown stellar streams related to accretion at two smaller companions: a flea fleas biting it, put it Jonathan Swift's words. Our data provide direct observational evidence multiple merging occurring very low galactic mass scales. results an...
Classical Cepheids (DCEPs) are the most important primary indicators of extragalactic distance scale. Establishing dependence on metallicity their period--luminosity and period--Wesenheit ($PLZ$/$PWZ$) relations has deep consequences calibration secondary that lead to final estimate Hubble constant (H$_0$). We collected high-resolution spectroscopy for 47 DCEPs plus 1 BL Her variables with HARPS-N@TNG derived accurate atmospheric parameters, radial velocities metal abundances. measured...
We derive the spatially-resolved star formation history (SFH) for a $96$ deg$^2$ area across main body of Large Magellanic Cloud (LMC), using near-infrared photometry from VISTA survey Clouds (VMC). The data and analyses are characterised by great degree homogeneity low sensitivity to interstellar extinction. 756 subregions size $0.125$ -- corresponding projected sizes about $296\times322\,\mathrm{pc}^{2}$ in LMC analysed. resulting SFH maps, with typical resolution $0.2$--$0.3$ dex...
The Planck satellite has identified more than 2000 protocluster candidates with extreme star formation rates (SFRs). Here, we present the spectroscopic identification of a Planck-selected located in Cosmos field, PHz G237.01+42.50 (G237). G237 contains galaxy overdensity 31 spectroscopically galaxies at z~2.16 (significant 5.4 sigma) 10'x11' region. two substructures or protoclusters <z>~2.16 and 2.195 estimated halo masses z=0 ~(5-6)x10^14 Msun. total SFR, ~4000 Msun/yr, is higher predicted...
ABSTRACT Classical Cepheids (DCEPs) are the most important standard candles in extra-galactic distance scale thanks to period–luminosity ($\rm PL$), period–luminosity–colour PLC$), and period–Wesenheit PW$) relations that hold for these objects. The advent of Gaia mission, particular Early Data Release 3 (EDR3), provided accurate parallaxes calibrate relations. In order fully exploit measurements, zero point (ZP) should be determined with an accuracy a few $\rm \mu as$. individual ZP...
Using Georgia State University's CHARA Array interferometer, we measured angular diameters for 25 giant stars, six of which host exoplanets. The combination these measurements and Hipparcos parallaxes produce physical linear radii the sample. Except two outliers, our values match estimated using photometric methods to within associated errors with advantage that uncertainties are significantly lower. We also calculated effective temperatures stars newly-measured diameters. Our do not those...
Abstract We report the discovery of a new ultra-short-period planet and summarize properties all such planets for which mass radius have been measured. The planet, K2-131b, was discovered in K2 Campaign 10. It has <?CDATA ${1.81}_{-0.12}^{+0.16}\,{R}_{\oplus }$?> orbits G dwarf with period 8.9 hr. Radial velocities obtained Magellan /PFS TNG/HARPS-N show evidence stellar activity along orbital motion. determined planetary using two different methods: (1) “floating chunk offset” method, based...
We announce the discovery of K2-139 b (EPIC 218916923 b), a transiting warm-Jupiter (Teq = 547 ± 25 K) on 29-d orbit around an active (log |$R^\prime _\mathrm{HK}$| −4.46 0.06) K0 V star in K2 Campaign 7. derive system's parameters by combining photometry with ground-based follow-up observations. With mass |$0.387 _{ - 0.075 } ^ {+ 0.083 }$|MJ and radius |$0.808 0.033 0.034 }$|RJ, is one warm Jupiters lowest known to date. The planetary mean density |$0.91 0.20} { + 0.24 }$| g cm−3can be...
STEP (the SMC in Time: Evolution of a Prototype interacting late-type dwarf galaxy) is Guaranteed Time Observation survey being performed at the VST ESO VLT Survey Telescope). will image an area 74 deg$^2$ covering main body Small Magellanic Cloud (32 deg$^2$), Bridge that connects it to Large (30 deg$^2$) and small part Stream (2 deg$^2$). Our $g,r,i,H_{\alpha}$ photometry able resolve individual stars down magnitudes well below main-sequence turnoff oldest populations. In this first paper...
Gaia16aye was a binary microlensing event discovered in the direction towards northern Galactic disc and one of first events detected alerted to by Gaia space mission. Its light curve exhibited five distinct brightening episodes, reaching up I=12 mag, it covered great detail with almost 25,000 data points gathered network telescopes. We present photometric spectroscopic follow-up covering 500 days evolution. employed full Keplerian orbit model combined motion Earth around Sun reproduce...
We present results from an analysis of $\sim$ 29,000 RR Lyrae stars located in the Large Magellanic Cloud (LMC). For these objects, near-infrared time-series photometry VISTA survey Clouds system (VMC) and optical data OGLE (Optical Gravitational Lensing Experiment) IV Gaia Data Release 2 catalogue confirmed were exploited. Using VMC magnitudes we derived period-luminosity (PL), period-luminosity-metallicity (PLZ), period-Wesenheit (PW) period-Wesenheit-metallicity (PWZ) relations all...