Latest in astro-ph.ga

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Investigating dynamical properties of evolved Galactic open clustersFeb 21 2019The stellar content of Galactic open clusters is gradually depleted during their evolution as a result of internal relaxation and external interactions. The final residues of the evolution of open clusters are called open cluster remnants, barely distinguishable ... More
Variable stars in Palomar 13; an evaporating globular clusterFeb 21 2019We present new CCD $VI$ photometry of the distant globular cluster Pal 13. Fourier decomposition of the light curves of the three cluster member RRab stars lead to estimations of [Fe/H]=-1.65, and a distance of 23.67$\pm$0.57 kpc. Light and colour near ... More
TREVR: A general $N log^2 N$ radiative transfer algorithmFeb 21 2019We present TREVR (Tree-based REVerse Ray Tracing), a general algorithm for computing the radiation field, including absorption, in astrophysical simulations. TREVR is designed to handle large numbers of sources and absorbers; it is based on a tree data ... More
The first Super Massive Black Holes: indications from models for future observationsFeb 21 2019We present an exploration of the expected detection of the earliest Active Galactic Nuclei (AGN) in the Universe from state-of-art galaxy formation and evolution semi-analytic models and hydro-dynamical simulations. We estimate the number and radiative ... More
Pégase.3: A code for modeling the UV-to-IR/submm spectral and chemical evolution of galaxies with dustFeb 21 2019A code computing consistently the evolution of stars, gas and dust, as well as the energy they radiate, is required to derive reliably the history of galaxies by fitting synthetic SEDs to multiwavelength observations. The new code P\'egase.3 described ... More
Detecting the Sagittarius stream with LAMOST DR4 M giants \& Gaia DR2Feb 21 2019We use LAMOST DR4 M giants combined with Gaia DR2 proper motions and ALLWISE photometry to obtain an extremely pure sample of Sagittarius (Sgr) stream stars. Using TiO5 and CaH spectral indices as an indicator, we selected out a large sample of M giant ... More
The JCMT BISTRO Survey: The Magnetic Field In The Starless Core $ρ$ Ophiuchus CFeb 20 2019We report 850~$\mu$m dust polarization observations of a low-mass ($\sim$12 $M_{\odot}$) starless core in the $\rho$ Ophiuchus cloud, Ophiuchus C, made with the POL-2 instrument on the James Clerk Maxwell Telescope (JCMT) as part of the JCMT B-fields ... More
$\texttt{Chronostar}$: a novel Bayesian method for kinematic age determination. I. Derivation and application to the $β$ Pictoris Moving GroupFeb 20 2019$\textit{Gaia}$ DR2 provides an unprecedented sample of stars with full 6D phase-space measurements, creating the need for a self-consistent means of discovering and characterising the phase-space overdensities known as $\textit{moving groups}$ or $\textit{associations}$. ... More
Prevalence of radio jets associated with galactic outflows and feedback from quasarsFeb 20 2019We present 1-7 GHz high-resolution radio imaging (VLA and e-MERLIN) and spatially-resolved ionized gas kinematics for ten z<0.2 type~2 `obscured' quasars (log [L(AGN)/(erg/s)]>~45) with moderate radio luminosities (log [L(1.4GHz)/(W/Hz)]=23.3-24.4). These ... More
BSE versus StarTrack: implementations of new wind, remnant-formation, and natal-kick schemes in NBODY7 and their astrophysical consequencesFeb 20 2019The masses of stellar-remnant black holes (BH), as a result of their formation via massive single- and binary-stellar evolution, is of high interest in this era of gravitational-wave detection from binary black hole (BBH) and binary neutron star (BNS) ... More
Constraining the Tail-End of Reionization Using Lyman-$α$ Transmission SpikesFeb 20 2019We investigate Lyman-$\alpha$ transmission spikes at $z > 5$ in synthetic quasar spectra, and discuss their connection to the properties of the intergalactic medium and their ability to constrain reionization models. We use state-of-the-art radiation-hydrodynamic ... More
A Catalogue of OB Stars from LAMOST Spectroscopic SurveyFeb 20 2019We present 22\,901 OB spectra of 16\,032 stars identified from LAMOST DR5 dataset. A larger sample of OB candidates are firstly selected from the distributions in the spectral line indices space. Then all 22\,901 OB spectra are identified by manual inspection. ... More
A census of $ρ$-Oph candidate members from \gaia DR2Feb 20 2019Rho-Ophiuchus (Rho-Oph), one of the nearest star forming regions, is an ideal laboratory to study the earlier stages of the stellar and protoplanetary disc evolution. We aim to find potential new members of the Rho-Oph region and identify those surrounded ... More
The Period-Luminosity Relations of Red Supergiants in M33 and M31Feb 20 2019Based on previously selected preliminary samples of Red Supergiants (RSGs) in M33 and M31, the foreground stars and luminous Asymptotic Giant Branch stars (AGBs) are further excluded, which leads to the samples of 717 RSGs in M33 and 420 RSGs in M31. ... More
Spatially resolved stellar mass buildup and quenching in massive disk galaxies over the last 10 Gyr revealed with spatially resolved SED fittingFeb 20 2019Despite decreasing cosmic star formation rate density over the last 10 Gyr, the stellar mass ($M_{*}$) buildups in galaxies were still progressing during this epoch. About 50\% of the current $M_{*}$ density in the universe was built over the last $\sim ... More
Unveiling a cluster of protostellar disks around the massive protostar GGD27 MM1Feb 20 2019We used ALMA to observe the star-forming region GGD27 at 1.14 mm with an unprecedented angular resolution, 40 mas (56 au) and sensitivity (0.002 Msun). We detected a cluster of 25 continuum sources, most of which are likely tracing disks around Class ... More
High-resolution radio imaging of the gamma-ray blazar candidate J1331+2932Feb 20 2019Active galactic nuclei are the most luminous persistent (non-transient, even if often variable) objects in the Universe. They are bright in the entire electromagnetic spectrum. Blazars are a special class where the jets point nearly to our line of sight. ... More
Unraveling the complex structure of AGN-driven outflows: IV. Comparing AGNs with and without strong outflowsFeb 20 2019AGN-driven outflows are considered as one of the processes driving the co-evolution of supermassive black holes with their host galaxies. We present integral field spectroscopy of six Type 2 AGNs at z < 0.1, which are selected as AGNs without strong outflows ... More
Asymmetric mid-plane gas in ALMA images of HD~100546Feb 20 2019In this paper we present new ALMA observations towards the proto-planet hosting transitional disc of Herbig Ae/Be star HD 100546. This includes resolved 1.3 mm continuum, $^{13}$CO and the first detection of C$^{18}$O in this disc, which displays azimuthal ... More
The rise and fall of a binary AGN candidate: the story of PSO J334.2028+1.4075Feb 20 2019Apparently periodic optical variations of the luminous high-redshift (z=2.06) quasar PSO J334.2028+1.4075 led Liu et al. (2015) to interpret the variability as the orbital period of a binary supermassive black hole (SMBH) residing in a single circumbinary ... More
The motion of a losing mass plasmonFeb 20 2019The interaction of a high velocity clump of gas has been described by the plasmon model, which considers balance between ram pressure and the internal stratified structure of the decelerated clump. In this paper we propose an analytical model to describe ... More
SDSS-IV MaNGA: Environmental dependence of the Mgb/<Fe>-sigma_* relation for nearby galaxiesFeb 20 2019We use a sample of ~3000 galaxies from the MaNGA MPL-7 internal data release to study the alpha abundance distribution within low-redshift galaxies. We use the Lick index ratio Mgb/<Fe> as an alpha abundance indicator to study relationships between the ... More
An Infrared Census Of Dust In Nearby Galaxies With Spitzer (dustings): V. The Period-luminosity Relation For Dusty Metal-poor Agb StarsFeb 20 2019The survey for DUST In Nearby Galaxies with Spitzer (DUSTiNGS) has identified hundreds of candidate dust-producing Asymptotic Giant Branch (AGB) stars in several nearby metal-poor galaxies. We have obtained multi-epoch follow-up observations for these ... More
A treatment procedure for GMOS/IFU data cubes: application to NGC 2835Feb 19 2019We present a set of treatment techniques for GMOS/IFU data cubes, including: correction of the differential atmospheric refraction; Butterworth spatial filtering, to remove high spatial-frequency noise; instrumental fingerprint removal; Richardson-Lucy ... More
Three little radio galaxies in the early UniverseFeb 19 2019Volonteri et al. (2011) found that the number of radio-loud quasars above redshift 4 calculated from the luminosity function (based upon Swift/BAT observations) is much smaller than the number estimated from the known high-redshift beamed sources, blazars, ... More
Kinematics of the Tucana Dwarf Galaxy: An Unusually Dense Dwarf in the Local GroupFeb 19 2019We present new FLAMES$+$GIRAFFE spectroscopy of 36 member stars in the isolated Local Group dwarf spheroidal galaxy Tucana. We measure a systemic velocity for the system of $v_{\mathrm{Tuc}}=216.7_{-2.8}^{+2.9}$kms$^{-1}$, and a velocity dispersion of ... More
Galaxy Merger Fractions in Two Clusters at $z\sim2$ Using the Hubble Space TelescopeFeb 19 2019We measure the fraction of galaxy-galaxy mergers in two clusters at $z\sim2$ using imaging and grism observations from the {\it Hubble Space Telescope}. The two galaxy cluster candidates were originally identified as overdensities of objects using deep ... More
The global stability of M33: still a puzzleFeb 19 2019The inner disc of the local group galaxy M33 appears to be in settled rotational balance, and near IR images reveal a mild, large-scale, two-arm spiral pattern with no strong bar. We have constructed N-body models that match all the extensive observational ... More
Spectroscopic Detection of a Cusp of Late-type Stars around the Central Black Hole in the Milky WayFeb 19 2019In a dynamically relaxed cluster around a massive black hole a dense stellar cusp of old stars is expected to form. Previous observations showed a relative paucity of red giant stars within the central 0.5 pc in the Galactic Center. By co-adding spectroscopic ... More
Feature Selection for Better Spectral Characterization or: How I Learned to Start Worrying and Love EnsemblesFeb 19 2019An ever-looming threat to astronomical applications of machine learning is the danger of over-fitting data, also known as the `curse of dimensionality.' This occurs when there are fewer samples than the number of independent variables. In this work, we ... More
Extended stellar systems in the solar neighborhood - III. Like ships in the night: the Coma Berenices neighbor moving groupFeb 19 2019We report the discovery of a kinematically cold group of stars, located in the immediate neighborhood of the well-known star cluster Coma Berenices (Mel 111). To the limit of our sensitivity, the new group contains at least 162 members distributed in ... More
Buckling instability in tidally induced galactic barsFeb 19 2019Strong galactic bars produced in simulations tend to undergo a period of buckling instability that weakens and thickensthe m and forms a boxy/peanut structure in their central parts. This theoretical prediction has been confirmed by identifying such morphologies ... More
Buckling instability in tidally induced galactic barsFeb 19 2019Feb 20 2019Strong galactic bars produced in simulations tend to undergo a period of buckling instability that weakens and thickens them and forms a boxy/peanut structure in their central parts. This theoretical prediction has been confirmed by identifying such morphologies ... More
On the origin of central abundance drops in the intracluster medium of galaxy groups and clustersFeb 19 2019A central drop of ICM Fe abundance has been observed in several cool-core clusters. It has been proposed that this abundance drop may be due, at least partially, to the depletion of Fe into dust grains in the central, high-density regions. According to ... More
On the origin of central abundance drops in the intracluster medium of galaxy groups and clustersFeb 19 2019Feb 21 2019A central drop of ICM Fe abundance has been observed in several cool-core clusters. It has been proposed that this abundance drop may be due, at least partially, to the depletion of Fe into dust grains in the central, high-density regions. According to ... More
Methylamine and other simple N-bearing species in the hot cores NGC 6334I MM1-3Feb 19 2019In the search for the building blocks of life, nitrogen-bearing molecules are of particular interest since nitrogen-containing bonds are essential for the linking of amino acids and ultimately the formation of larger biological structures. The elusive ... More
Gravitational lensing at milliarcsecond angular resolution with VLBI observationsFeb 19 2019Gravitational lensing is a powerful tool for quantifying the mass content and distribution in distant galaxies. By using milliarcsecond angular resolution observations of radio-loud gravitationally lensed sources it is also possible to detect and quantify ... More
The halo mass of optically-luminous quasars at z=1-2 measured via gravitational deflection of the cosmic microwave backgroundFeb 19 2019We measure the average deflection of cosmic microwave background photons by quasars at $\langle z \rangle =1.7$. Our sample is selected from the Sloan Digital Sky Survey to cover the redshift range $0.9\leq z\leq2.2$ with absolute i-band magnitudes of ... More
The substructure and halo population of the Double Cluster $h$ and $χ$ PerseiFeb 19 2019In order to study the stellar population and possible substructures in the outskirts of Double Cluster $h$ and $\chi$ Persei, we investigate using the GAIA DR2 data a sky area of about 7.5 degrees in radius around the Double Cluster cores. We identify ... More
The Spectral Energy Distributions of Active Galactic NucleiFeb 19 2019We present ongoing work on the spectral energy distributions (SEDs) of active galactic nuclei (AGNs), derived from X-ray, ultraviolet, optical, infrared and radio photometry and spectroscopy. Our work is motivated by new wide-field imaging surveys that ... More
Chandra observations of the Abell S0295 clusterFeb 18 2019We present deep ($205 \rm ks$), \Chandra observations of the \ab295 binary merging cluster ($z=0.30$). In the X-ray image, the secondary component is clearly visible as a surface brightness peak, while the primary cluster has a flatter distribution. We ... More
Gemini NIFS survey of feeding and feedback in nearbyActive Galaxies - III. Ionized versus warm molecular gasmasses and distributionsFeb 18 2019We have used the Gemini Near-Infrared Integral Field Spectrograph (NIFS) in the J and K bands to map the distribution, excitation and kinematics of the ionized H\,{\sc ii} and warm molecular gas H$_2$, in the inner few 100\,pc of 6 nearby active galaxies: ... More
Thermal Phases of the Neutral Atomic Interstellar Medium - from Solar Metallicity to Primordial GasFeb 18 2019We study the thermal structure of the neutral atomic (H {\small I}) interstellar medium across a wide range of metallicities, from supersolar down to vanishing metallicity, and for varying UV intensities and cosmic-ray ionization rates. We calculate self-consistently ... More
Distinguishing Mergers and Disks in High Redshift Observations of Galaxy KinematicsFeb 18 2019The majority of massive star-forming galaxies at $z\sim2$ have velocity gradients suggestive of rotation, in addition to large amounts of disordered motions. In this paper, we demonstrate that it is challenging to distinguish the regular rotation of a ... More
First Identification of 10-kpc Scale [CII] 158um Halos around Star-Forming Galaxies at z=5-7Feb 18 2019We report the discovery of 10-kpc scale [CII] 158um halos surrounding star-forming galaxies in the early Universe. We choose deep ALMA data of 18 galaxies each with a star-formation rate of ~ 10-70 Msun with no signature of AGN whose [CII] lines are individually ... More
The 'Big Dipper': The nature of the extreme variability of the AGN SDSS J2232-0806Feb 18 2019SDSS J2232-0806 (the 'Big Dipper') has been identified as a 'slow-blue nuclear hypervariable': a galaxy with no previously known active nucleus, blue colours and large-amplitude brightness evolution occurring on a timescale of years. Subsequent observations ... More
NIHAO XVIII: Origin of the MOND phenomenology of galactic rotation curves in a LCDM universeFeb 18 2019The phenomenological basis for Modified Newtonian Dynamics (MOND) is the radial-acceleration-relation (RAR) between the observed acceleration, $a=V^2_{rot}(r)/r$, and the acceleration accounted for by the observed baryons (stars and cold gas), $a_{bar}=V_{bar}^2(r)/r$. ... More
A highly variable methanol maser in G111.256-0.770Feb 18 2019G111.256-0.770 is a high-mass young stellar object associated with a weak 6.7 GHz methanol maser showing strong variability. We present results of a multi-epoch monitoring program of the target, conducted with the Torun 32 m telescope for more than a ... More
The linear bias of radio galaxies at z~0.3 via cosmic microwave background lensingFeb 18 2019We present a new measurement of the linear bias of radio loud active galactic nuclei (RLAGN) at $z\approx0.3$ and $L_{\rm 1.4GHz}>10^{23}\,{\rm W\,Hz^{-1}}$ selected from the Best & Heckman (2012) sample, made by cross-correlating the RLAGN surface density ... More
Homogeneity of the universe emerging from the Equivalence Principle and Poisson equation: A comparison between Newtonian and MONDian cosmologyFeb 18 2019A correspondence between the Equivalence principle and the homogeneity of the universe is discussed. We show that under the Newtonian gravity, translation of co-moving coordinates in a uniformly expanding universe defines a new accelerated frame. A consistency ... More
New spectral characterization of dimethyl ether isotopologues CH$_3$OCH$_3$ and $^{13}$CH$_3$OCH$_3$ in the THz regionFeb 18 2019The torsional Raman spectra of two astrophysically detected isotopologues of dimethyl-ether, ($^{12}$CH$_3$O$^{12}$CH$_3$ and $^{13}$CH$_3$O$^{12}$CH$_3$), have been recorded at room temperature and cooled in supersonic jet, and interpreted with the help ... More
Rotational Desorption of Ice Mantles and Complex Molecules from Suprathermally Rotating Dust Grains around Young Stellar ObjectsFeb 18 2019Complex organic molecules (COMs) are increasingly observed in the environs of young stellar objects (YSOs), including hot cores/corinos around high-mass/low-mass protostars and protoplanetary disks. It is widely believed that COMs are first formed in ... More
The mass-metallicity relation of local active galaxiesFeb 18 2019We systematically measure the gas-phase metallicities and the mass-metallicity relation of a large sample of local active galaxies for the first time. Observed emission-line fluxes from the Sloan Digital Sky Survey (SDSS) are compared to a four-dimensional ... More
Ejection History of the IRAS 04166+2706 Molecular JetFeb 16 2019The high-velocity molecular jet driven by Class 0 protostar IRAS 04166+2706 exhibits a unique saw-tooth velocity pattern. It consists of a series of well-aligned symmetric knots with similar averaged speeds, whose speeds at peaks of emission decreases ... More
Exploring HeII$λ$1640 emission line properties at ${z\sim2-4}$Feb 15 2019Deep optical spectroscopic surveys of galaxies provide us a unique opportunity to investigate rest-frame ultra-violet (UV) emission line properties of galaxies at ${z \sim 2-4.5}$. Here we combine VLT/MUSE Guaranteed Time Observations of the Hubble Deep ... More
On the Orbital Decay of Globular Clusters in NGC1052-DF2: Testing a Baryon-Only Mass ModelFeb 15 2019The dark matter content of the ultra diffuse galaxy NGC1052-DF2, as inferred from globular cluster (GC) and stellar kinematics, carries a considerable amount of uncertainty, with current constraints also allowing for the complete absence of dark matter. ... More
Chemical evolution of disc galaxies from cosmological simulationsFeb 15 2019We perform a suite of cosmological hydrodynamical simulations of disc galaxies, with zoomed-in initial conditions leading to the formation of a halo of mass $M_{\rm halo, \, DM} \simeq 2 \cdot 10^{12}$ M$_{\odot}$ at redshift $z=0$. These simulations ... More
The Mass Evolution of Protostellar Disks and Envelopes in the Perseus Molecular CloudFeb 15 2019In the standard picture for low-mass star formation, a dense molecular cloud undergoes gravitational collapse to form a protostellar system consisting of a new central star, a circumstellar disk, and a surrounding envelope of remaining material. The mass ... More
Multiplicity functions of quasars: Predictions from the MassiveBlackII simulationFeb 15 2019We examine simulated AGN systems (triples and quadruples, in particular) in the MassiveBlackII simulation. We identify AGN systems (with bolometric luminosity $L_{\mathrm{bol}}>10^{42}~\mathrm{ergs/sec}$) at different scales (defined by the maximum distance ... More
Simulations of the polarized radio sky and predictions on the confusion limit in polarization for future radio surveysFeb 15 2019Numerical simulations offer the unique possibility to forecast the results of surveys and targeted observations that will be performed with next generation instruments like the Square Kilometre Array. In this paper, we investigate for the first time how ... More
The Origin of Radio Emission from Radio-Quiet AGNFeb 15 2019The central nuclei of galaxies, where super-massive black holes (SMBHs) are thought to reside, can experience phases of activity when they become Active Galactic Nuclei (AGN). An AGN can eject winds, jets, and produce radiation across the entire electromagnetic ... More
Analytical model for the dynamical motion of the bulges of two interacting galaxiesFeb 15 2019Two mathematical models of three bodies of variable masses are used to obtain a qualitative description of two interacting galaxies with mass exchange and mass loss. The reference system is centred on the largest body (the most massive galaxy), and the ... More
The eye of Gaia on globular clusters kinematics: internal rotationFeb 15 2019We derived the three-dimensional velocities of individual stars in a sample of 62 Galactic globular clusters using proper motions from the second data release of the Gaia mission together with the most comprehensive set of line-of-sight velocities with ... More
The blue straggler population of the old open cluster Berkeley 17Feb 15 2019Blue Straggler Stars (BSSs) are observed in Galactic globular clusters and old open clusters. The radial distribution of BSSs has been used to diagnose the dynamical evolution of globular clusters. For the first time, with a reliable sample of BSSs identified ... More
Optical detection of a GMRT-detected candidate high-redshift radio galaxy with 3.6-m Devasthal optical telescopeFeb 15 2019We report optical observations of TGSS J1054+5832, a candidate high-redshift ($z=4.8\pm2$) steep-spectrum radio galaxy, in $r$ and $i$ bands using the faint object spectrograph and camera mounted on 3.6-m Devasthal Optical Telescope (DOT). The source ... More
Submillimeter spectroscopy and astronomical searches of vinyl mercaptan, C$_2$H$_3$SHFeb 15 2019We have extended the pure rotational investigation of the two isomers syn and anti vinyl mercaptan to the millimeter domain using a frequency-multiplication spectrometer. The species were produced by a radiofrequency discharge in 1,2-ethanedithiol. Additional ... More
Extra-tidal structures around the Gaia Sausage candidate globular cluster NGC6779 (M56)Feb 15 2019We present results on the stellar density radial profile of the outer regions of NGC6779, a Milky Way globular cluster recently proposed as a candidate member of the Gaia Sausage structure, a merger remnant of a massive dwarf galaxy with the Milky Way. ... More
M31 circum-nuclear region: a molecular survey with the IRAM-interferometerFeb 15 2019We analyse molecular observations performed at IRAM interferometer in CO(1-0) of the circum-nuclear region (within 250 pc) of Andromeda, with 2.9 arcsec = 11 pc resolution. We detect 12 molecular clumps in this region, corresponding to a total molecular ... More
Ruprecht 147 DANCe I. Members, empirical isochrone, luminosity and mass distributionsFeb 15 2019Context. Ruprecht 147 is the oldest (2.5 Gyr) open cluster in the solar vicinity (< 300 pc), making it an important target for stellar evolution studies and exoplanet searches. Aims. Derive a census of members and the luminosity, mass, and spatial distributions ... More
The core and stellar mass functions in massive collapsing filamentsFeb 15 2019The connection between the pre-stellar core mass function (CMF) and the stellar initial mass function (IMF) lies at the heart of all star formation theories. In this paper, we study the earliest phases of star formation with a series of high-resolution ... More
Magnetic field vector maps of nearby spiral galaxiesFeb 15 2019We present a method for determining directions of magnetic field vectors in a spiral galaxy using two synchrotron polarization maps, an optical image, and a velocity field. The orientation of the transverse magnetic field is determined with a synchrotron ... More
The SAMI Galaxy Survey: Satellite galaxies undergo little structural change during their quenching phaseFeb 15 2019At fixed stellar mass, satellite galaxies show higher passive fractions than centrals, suggesting that environment is directly quenching their star formation. Here, we investigate whether satellite quenching is accompanied by changes in stellar spin (quantified ... More
Mapping the Interstellar Reddening and Extinction towards Baade's Window Using Minimum Light Colors of ab-type RR Lyrae Stars. Revelations from the De-reddened Color-Magnitude DiagramsFeb 14 2019We have obtained repeated images of 6 fields towards the Galactic bulge in 5 passbands (u, g, r, i, z) with the DECam imager on the Blanco 4m telescope at CTIO. From over 1.6 billion individual photometric measurements in the field centered on Baade's ... More
The Wide Field Infrared Survey Telescope: 100 Hubbles for the 2020sFeb 14 2019The Wide Field Infrared Survey Telescope (WFIRST) is a 2.4m space telescope with a 0.281 deg^2 field of view for near-IR imaging and slitless spectroscopy and a coronagraph designed for > 10^8 starlight suppresion. As background information for Astro2020 ... More
A panchromatic view of the bulge globular cluster NGC 6569Feb 14 2019We used high-resolution optical HST/WFC3 and multi-conjugate adaptive optics assisted GEMINI GeMS/GSAOI observations in the near-infrared to investigate the physical properties of the globular cluster NGC 6569 in the Galactic bulge. We have obtained the ... More
First Results from the TNG50 Simulation: Galactic outflows driven by supernovae and black hole feedbackFeb 14 2019We present the new TNG50 cosmological, magnetohydrodynamical simulation -- the third and final volume of the IllustrisTNG project. This simulation occupies a unique combination of large volume and high resolution, with a 50 Mpc box sampled by 2160^3 gas ... More
Accretion disk versus jet orientation in H$_{2}$O megamaser galaxiesFeb 14 2019An essential part of the paradigm describing active galactic nuclei is the alignment between the radio jet and the associated rotation axis of the sub-pc sized accretion disks. Because of the small linear and angular scales involved, this alignment has ... More
Orientation effects on the near-infrared broad band emission of quasarsFeb 14 2019We recently proposed the equivalent width (EW) of the narrow [OIII]5007{\AA} emission line as an orientation indicator for active galactic nuclei. We tested this method on about $12,300$ optically selected broad line quasars from the SDSS 7th Data Release ... More
A Code to Make Your Own Synthetic ObservaTIonS (MYOSOTIS)Feb 14 2019We introduce our new code MYOSOTIS (Make Your Own Synthetic ObservaTIonS) which is designed to produce synthetic observations from simulated clusters. The code can synthesise observations from both ground- and spaced-based observatories, for a range of ... More
Searching for Highly Magnified Stars at Cosmological Distances: Discovery of a Redshift 0.94 Blue Supergiant in Archival Images of the Galaxy Cluster MACS J0416.1-2403Feb 14 2019Individual highly magnified stars have been recently discovered at lookback times of more than half the age of the Universe, in lensed galaxies that straddle the critical curves of massive galaxy clusters. Having confirmed their detectability, it is now ... More
A semi-analytical perspective on massive galaxies at $z\sim0.55$Feb 14 2019The most massive and luminous galaxies in the Universe serve as powerful probes to study the formation of structure, the assembly of mass, and cosmology. However, their detailed formation and evolution is still barely understood. Here we extract a sample ... More
Cosmological evolution of quasar radio emission in the view of multifractalityFeb 14 2019Variations in scaling behavior in the flux and emissions of distant astronomical sources with respect to their cosmic time are important l phenomena that can provide valuable information about the dynamics within the sources and their cosmological evolution ... More
Near-infrared spectroscopy of the massive stellar population of W51: evidence for multi-seeded star formationFeb 14 2019The interplay between the formation of stars, stellar feedback and cloud properties strongly influences the star formation history of giant molecular clouds. The formation of massive stars leads to a variety of stellar clusters, ranging from low stellar ... More
Galaxy Evolution in ClustersFeb 14 2019In this thesis, we aim to further elucidate the phenomenon of galaxy evolution in the environment of galaxy clusters using the methodology of numerical simulations. For that, we have developed hydrodynamic models in which idealized gas-rich galaxies move ... More
The central 1000 AU of a pre-stellar core revealed with ALMA. I. 1.3 mm continuum observationsFeb 14 2019Stars like our Sun form in self-gravitating dense and cold structures within interstellar clouds, called pre-stellar cores. Although much is known about the physical structure of dense clouds just before and soon after the switch-on of a protostar, the ... More
A morphological study of galaxies in ZwCl0024+1652, a galaxy cluster at redshift z $\sim$ 0.4Feb 14 2019The well-known cluster of galaxies ZwCl0024+1652 at z $\sim$ 0.4, lacks an in-depth morphological classification of its central region. While previous studies provide a visual classification of a patched area, we used the public code called galaxy Support ... More
The tilt of the velocity ellipsoid in the Milky Way with Gaia DR2Feb 14 2019The velocity distribution of stars is a sensitive probe of the gravitational potential of the Galaxy, and hence of its dark matter distribution. In particular, the shape of the dark halo (e.g. spherical, oblate, prolate) determines velocity correlations, ... More
Uncovering the progenitor of the Cetus stream with StarGO -- a low mass dwarf with a nuclear star clusterFeb 14 2019Feb 15 2019We use a novel cluster identification tool StarGO to explore the metal poor ([Fe/H] $<$ -1.5) outer stellar halo (d $>$ 15 kpc) of the Milky Way using data from Gaia, LAMOST and SDSS. Our method is built using an unsupervised learning algorithm, a self-organizing ... More
Uncovering the progenitor of the Cetus stream with StarGO -- a low mass dwarf with a nuclear star clusterFeb 14 2019We use a novel cluster identification tool StarGO to explore the metal poor ([Fe/H] $<$ -1.5) outer stellar halo (d $>$ 15 kpc) of the Milky Way using data from Gaia, LAMOST and SDSS. Our method is built using an unsupervised learning algorithm, a self-organizing ... More
Strong Lensing considerations for the LSST observing strategyFeb 13 2019Strong gravitational lensing enables a wide range of science: probing cosmography; testing dark matter models; understanding galaxy evolution; and magnifying the faint, small and distant Universe. However to date exploiting strong lensing as a tool for ... More
Herschel water maps towards the vicinity of the black hole Sgr A*Feb 13 2019Aims: We study the spatial distribution and kinematics of water emission in a ~64 pc$^2$ region of the Galactic Center (GC) around Sgr A*. We also analyze the water excitation to derive the physical conditions and water abundances in the CND and the `quiescent ... More
Hunting for the Dark Matter Wake Induced by the Large Magellanic CloudFeb 13 2019Satellite galaxies are predicted to generate gravitational density wakes as they orbit within the dark matter (DM) halos of their hosts, causing their orbits to decay over time. The recent infall of the Milky Way's (MW) most massive satellite galaxy, ... More
Using Commensurabilities and Orbit Structure to Understand Barred Galaxy EvolutionFeb 13 2019We interpret simulations of secularly-evolving disc galaxies through orbit morphology. Using a new geometric algorithm that rapidly isolates commensurate (resonant) orbits, we identify phase-space regions occupied by different orbital families. Compared ... More
Modelling the observed luminosity function and clustering evolution of Lyman-$α$ emitters: growing evidence for late reionizationFeb 13 2019We model the high redshift (z > 5) Lyman-$\alpha$ emitting (LAE) galaxy population using the empirical rest-frame equivalent width distribution. We calibrate to the observed luminosity function and angular correlation function at z = 5.7 as measured by ... More
Relationship between the Line Width of the Atomic and Molecular ISM in M33Feb 13 2019We investigate how the spectral properties of atomic (HI) and molecular (H$_2$) gas, traced by CO(2-1), are related in M33 on $80$ pc scales. We find the HI and CO(2-1) velocity at peak intensity to be highly correlated, consistent with previous studies. ... More
Estimating the Integrated Bispectrum from Weak Lensing MapsFeb 13 2019We use a recently introduced statistic called Integrated Bispectrum (IB) to probe the gravity-induced non-Gaussianity at the level of the bispectrum from weak lensing convergence or $\kappa$ maps. We generalize the concept of the IB to spherical coordinates, ... More
What determines the shape of the local (z<0.1) infrared galaxy luminosity function?Feb 13 2019We investigate what shapes the infrared luminosity function of local galaxies by comparing it to the local infrared AGN luminosity function. The former corresponds to emission from dust heated by stars and AGN, whereas the latter includes emission from ... More
Results from the SuperModel Analysis of the X-COP Galaxy Clusters SampleFeb 13 2019In this work, the analysis of the stacked projected temperature profile of twelve galaxy clusters of the X-COP sample is performed via the SuperModel, a tool for investigating the intracluster medium thermodynamic properties already tested on many clusters ... More
Cavities, shocks and a cold front around 3C 320Feb 13 2019We present results obtained from the analysis of a total of 110 ks Chandra observations of 3C 320 FR II radio galaxy, located at the centre of a cluster of galaxies at a redshift $z=0.342$. A pair of X-ray cavities have been detected at an average distance ... More
The substructures in the local stellar halo from Gaia and LAMOSTFeb 13 2019Based on the second Gaia data release (Gaia DR2) and spectroscopy from the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) Data, we identified 20,089 halo stars kinematically and chemically. The halo streams in the solar neighborhood ... More