- ID:
- ivo://CDS.VizieR/J/ApJ/762/46
- Title:
- SHARDS: GOODS-N spectrophotometry survey
- Short Name:
- J/ApJ/762/46
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the Survey for High-z Absorption Red and Dead Sources (SHARDS), an ESO/GTC Large Program carried out using the OSIRIS instrument on the 10.4m Gran Telescopio Canarias (GTC). SHARDS is an ultra-deep optical spectro-photometric survey of the GOODS-N field covering 130arcmin2 at wavelengths between 500 and 950nm with 24 contiguous medium-band filters (providing a spectral resolution R~50). The data reach an AB magnitude of 26.5 (at least at a 3{sigma} level) with sub-arcsec seeing in all bands. SHARDS' main goal is to obtain accurate physical properties of intermediate- and high-z galaxies using well-sampled optical spectral energy distributions (SEDs) with sufficient spectral resolution to measure absorption and emission features, whose analysis will provide reliable stellar population and active galactic nucleus (AGN) parameters. Among the different populations of high-z galaxies, SHARDS' principal targets are massive quiescent galaxies at z>1, whose existence is one of the major challenges facing current hierarchical models of galaxy formation. In this paper, we outline the observational strategy and include a detailed discussion of the special reduction and calibration procedures which should be applied to the GTC/OSIRIS data. An assessment of the SHARDS data quality is also performed. We present science demonstration results on the detection and study of emission-line galaxies (star-forming objects and AGNs) at z=0-5. We also analyze the SEDs for a sample of 27 quiescent massive galaxies with spectroscopic redshifts in the range 1.0<z<~1.4.
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Search Results
- ID:
- ivo://CDS.VizieR/J/ApJS/239/2
- Title:
- Simulated exoplanets from TESS list of targets
- Short Name:
- J/ApJS/239/2
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Transiting Exoplanet Survey Satellite (TESS) has a goal of detecting small planets orbiting stars bright enough for mass determination via ground-based radial velocity observations. Here, we present estimates of how many exoplanets the TESS mission will detect, the physical properties of the detected planets, and the properties of the stars that those planets orbit. This work uses stars drawn from the TESS Input Catalog (TIC) Candidate Target List and revises yields from prior studies that were based on Galactic models. We modeled the TESS observing strategy to select approximately 200000 stars at 2-minute cadence, while the remaining stars are observed at 30-minute cadence in full-frame image data. We placed zero or more planets in orbit around each star, with physical properties following measured exoplanet occurrence rates, and used the TESS noise model to predict the derived properties of the detected exoplanets. In the TESS 2-minute cadence mode we estimate that TESS will find 1250+/-70 exoplanets (90% confidence), including 250 smaller than 2R_{Earth}_. Furthermore, we predict that an additional 3100 planets will be found in full-frame image data orbiting bright dwarf stars and more than 10000 around fainter stars. We predict that TESS will find 500 planets orbiting M dwarfs, but the majority of planets will orbit stars larger than the Sun. Our simulated sample of planets contains hundreds of small planets amenable to radial velocity follow-up, potentially more than tripling the number of planets smaller than 4R_{Earth}_ with mass measurements. This sample of simulated planets is available for use in planning follow-up observations and analyses.
- ID:
- ivo://CDS.VizieR/J/A+A/655/A46
- Title:
- Simulated IR spectra of PN Hubble 12
- Short Name:
- J/A+A/655/A46
- Date:
- 10 Mar 2022 07:09:39
- Publisher:
- CDS
- Description:
- We present a visible-infrared imaging study of young planetary nebula (PN) Hubble 12 (Hb 12; PN G111.8-02.8) obtained with Hubble Space Telescope (HST) archival data and our own Canada-France-Hawaii Telescope (CFHT) measurements. Deep HST and CFHT observations of this nebula reveal three pairs of bipolar structures and an arc-shaped filament near the western waist of Hb 12. The existence of nested bipolar lobes together with the presence of H2 knots suggests that these structures originated from several mass-ejection events during the pre-PN phase. To understand the intrinsic structures of Hb 12, a three-dimensional model enabling the visualisation of this PN at various orientations was constructed. The modelling results show that Hb 12 may resemble other nested hourglass nebulae, such as Hen 2-320 and M 2-9, suggesting that this type of PN may be common and the morphologies of PNs are not so diverse as is shown by their visual appearances. The infrared spectra show that this PN has a mixed chemistry. We discuss the possible material that may cause the unidentified infrared emissions. The analyses of the infrared spectra and the spectral energy distribution suggest the existence of a cool companion in the nucleus of this object.
- ID:
- ivo://CDS.VizieR/J/MNRAS/454/3771
- Title:
- Simulated spectral evolution of black holes
- Short Name:
- J/MNRAS/454/3771
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Massive black hole (MBH) seeds at redshift z>~10 are now thought to be key ingredients to explain the presence of the supermassive (10^9-10^M_{sun}_) black holes in place <1Gyr after the big bang. Once formed, massive seeds grow and emit copious amounts of radiation by accreting the left-over halo gas; their spectrum can then provide crucial information on their evolution. By combining radiation-hydrodynamic and spectral synthesis codes, we simulate the time-evolving spectrum emerging from the host halo of a MBH seed with initial mass 10^5^M_{sun}_, assuming both standard Eddington-limited accretion, or slim accretion discs, appropriate for super-Eddington flows. The emission occurs predominantly in the observed infrared-submm (1-1000{mu}m) and X-ray (0.1-100keV) bands. Such signal should be easily detectable by JWST around ~1{mu}m up to z~25, and by ATHENA (between 0.1 and 10keV, up to z~15). Ultra-deep X-ray surveys like the Chandra Deep Field South could have already detected these systems up to z~15. Based on this, we provide an upper limit for the z>~6 MBH mass density of {rho}{blackdot}<~2.5x10^2^M_{sun}_/Mpc^3^ assuming standard Eddington-limited accretion. If accretion occurs in the slim disc mode the limits are much weaker, {rho}{blackdot}<~7.6x10^3^M_{sun}_/Mpc^3^ in the most constraining case.
- ID:
- ivo://CDS.VizieR/J/MNRAS/399/323
- Title:
- Simulated UVEX colors with reddening
- Short Name:
- J/MNRAS/399/323
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The UV-Excess survey of the northern Galactic plane images a 10{deg}x185{deg} wide band, centred on the Galactic equator using the 2.5-m Isaac Newton Telescope in four bands (U, g, r, HeI 5875) down to ~21-22mag (~20 in HeI 5875). The setup and data reduction procedures are described. Simulations of the colours of main-sequence stars, giant, supergiants, DA and DB white dwarfs and AM Canum Venaticorum stars are made, including the effects of reddening. A first look at the data of the survey (currently 30 per cent complete) is given.
- ID:
- ivo://CDS.VizieR/VI/76
- Title:
- Simulation Atlas of Tidal Features in Galaxies
- Short Name:
- VI/76
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The simulation survey of tidally perturbed galaxies provides images of 84 different encounters that vary orbit tilt of companion orbit, perigalacticon distance ratio of primary galaxy mass to companion mass, and the amount of inert matter in the primary galaxy. In total 1764 galaxy images are available in the survey. This data set contains 84 separate simulations, each simulation is run for 1000 time steps, producing image output of the star particles and gas particles separately every 50 time steps. The first 21 images represent the "gas", and the second 21 images represent the "stars". Time steps for matching "gas" and "stars" are the same. There are [256,256] grid points on a Cartesian coordinate system. The renormalized densities are stored as 8-bit floating point numbers. The data have been put into FITS. Each header specifies the parameters for that simulation.
- ID:
- ivo://CDS.VizieR/J/MNRAS/448/1044
- Title:
- Simulation data for 50 planetary model systems
- Short Name:
- J/MNRAS/448/1044
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We describe the long-term evolution of compact systems of terrestrial planets, using a set of simulations that match the statistical properties of the observed exoplanet distribution. The evolution is driven by tidal dissipation in the planetary interiors, but the systems evolve as a whole due to secular gravitational interactions. We find that, for Earth-like dissipation levels, planetary orbits can be circularized out to periods ~100 d, an order of magnitude larger than is possible for single planets. The resulting distribution of eccentricities is a qualitative match to that inferred from transit timing variations, with a minority of non-zero eccentricities maintained by particular secular configurations. The coupling of the tidal and secular processes enhance the inward migration of the innermost planets in these systems, and can drive them to short orbital periods. Resonant interactions of both the mean motion and secular variety are observed, although the interactions are not strong enough to drive systemic instability in most cases. However, we demonstrate that these systems can easily be driven unstable if coupled to giant planets on longer period orbits.
- ID:
- ivo://CDS.VizieR/J/A+A/559/A62
- Title:
- Simulations of dust aggregates through collisions
- Short Name:
- J/A+A/559/A62
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Collisional growth of dust aggregates is an essential process to form planetesimals in protoplanetary disks, but disruption through high-velocity collisions (disruption barrier) could prohibit the dust growth. Mass transfer through highly different-sized collisions has been suggested to be a way to circumvent the disruption barrier. We examine how the collisional growth efficiency of dust aggregates at different impact parameters depends on the size and the mass-ratio of colliding aggregates. We use an N-body code to numerically simulate the collisions of different-sized aggregates. Our results show that large values of the impact parameter are important and the growth efficiency averaged over the impact parameter does not depend on the aggregate size although the growth efficiency for nearly head-on collisions increases with size. We also find that the averaged growth efficiency tends to increase with increasing the mass-ratio of colliding aggregates. However, the critical collision velocity, above which the growth efficiency becomes negative, does not strongly depend on the mass-ratio. These results indicate icy dust can grow through high-velocity offset collisions at several tens of m/s, the maximum collision velocity experienced in protoplanetary disks, whereas it is still difficult for silicate dust to grow in protoplanetary disks.
- ID:
- ivo://CDS.VizieR/J/A+A/586/A75
- Title:
- Simulations of hot gas planets atmospheres
- Short Name:
- J/A+A/586/A75
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Absorption of high-energy radiation in planetary thermospheres is generally believed to lead to the formation of planetary winds. The resulting mass-loss rates can affect the evolution, particularly of small gas planets. We present 1D, spherically symmetric hydrodynamic simulations of the escaping atmospheres of 18 hot gas planets in the solar neighborhood. Our sample only includes strongly irradiated planets, whose expanded atmospheres may be detectable via transit spectroscopy using current instrumentation. The simulations were performed with the PLUTO-CLOUDY interface, which couples a detailed photoionization and plasma simulation code with a general MHD code. We study the thermospheric escape and derive improved estimates for the planetary mass-loss rates. Our simulations reproduce the temperature-pressure profile measured via sodium D absorption in HD 189733 b, but show still unexplained differences in the case of HD 209458 b. In contrast to general assumptions, we find that the gravitationally more tightly bound thermospheres of massive and compact planets, such as HAT-P-2 b are hydrodynamically stable. Compact planets dispose of the radiative energy input through hydrogen Ly alpha and free-free emission. Radiative cooling is also important in HD 189733 b, but it decreases toward smaller planets like GJ 436 b. Computing the planetary Ly alpha absorption and emission signals from the simulations, we find that the strong and cool winds of smaller planets mainly cause strong Ly alpha absorption but little emission. Compact and massive planets with hot, stable thermospheres cause small absorption signals but are strong Ly{alpha} emitters, possibly detectable with the current instrumentation. The absorption and emission signals provide a possible distinction between these two classes of thermospheres in hot gas planets. According to our results, WASP-80 and GJ 3470 are currently the most promising targets for observational follow-up aimed at detecting atmospheric Ly{alpha} absorption signals.
- ID:
- ivo://CDS.VizieR/J/A+A/462/107
- Title:
- Simulations of metal-poor star clusters
- Short Name:
- J/A+A/462/107
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The intrinsic uncertainty (due to statistical effects) affecting the integrated colours and mass-to-light ratios as a function of the cluster's integrated visual magnitude (M_V^tot^_) is studied. We investigate the case of metal-poor, single-burst stellar populations with age from a few million years to a likely upper value for the Galactic globular cluster ages. Monte Carlo techniques are used for randomly generating stars distributed according to the cluster's mass function. Integrated colours and mass-to-light ratios in different photometric bands are presented as a function of age for different assumptions on the cluster total V magnitude and they are checked for good agreement with the observational values of low-metallicity Galactic clusters.
