Search Publications
On the redshift distribution and physical properties of ACT-selected DSFGs
Frayer, D. T.; Bond, J. R.; Partridge, B. +25 more
We present multi-wavelength detections of nine candidate gravitationally lensed dusty star-forming galaxies (DSFGs) selected at 218 GHz (1.4 mm) from the Atacama Cosmology Telescope (ACT) equatorial survey. Among the brightest ACT sources, these represent the subset of the total ACT sample lying in Herschel SPIRE fields, and all nine of the 218 GH…
Characterization of the VVV Survey RR Lyrae Population across the Southern Galactic Plane
Valenti, Elena; Minniti, Dante; Rejkuba, Marina +14 more
Deep near-IR images from the VISTA Variables in the Vía Láctea (VVV) Survey were used to search for RR Lyrae stars in the Southern Galactic plane. A sizable sample of 404 RR Lyrae of type ab stars was identified across a thin slice of the fourth Galactic quadrant (295° < ℓ < 350°, -2.°24 < b < -1.°05). The sample’s distance distributio…
Early cosmology constrained
Verde, Licia; Jimenez, Raul; Heavens, Alan F. +2 more
We investigate our knowledge of early universe cosmology by exploring how much additional energy density can be placed in different components beyond those in the ΛCDM model. To do this we use a method to separate early- and late-universe information enclosed in observational data, thus markedly reducing the model-dependency of the conclusions. We…
The power of teaming up HST and Gaia: the first proper motion measurement of the distant cluster NGC 2419
Massari, D.; Helmi, A.; Fiorentino, G. +2 more
Aims: We present the first measurement of the proper motion and orbit of the very distant and intriguing globular cluster NCG 2419.
Methods: We have combined data from HST and Gaia DR1 to derive the relative proper motions of stars in the direction of the cluster. To tie these to an absolute reference frame, we have used a background gal…
Non-local Thermodynamic Equilibrium Stellar Spectroscopy with 1D and >3D< Models. II. Chemical Properties of the Galactic Metal-poor Disk and the Halo
Kovalev, Mikhail; Hansen, Camilla Juul; Bergemann, Maria +5 more
From exploratory studies and theoretical expectations it is known that simplifying approximations in spectroscopic analysis (local thermodynamic equilibrium (LTE), 1D) lead to systematic biases of stellar parameters and abundances. These biases depend strongly on surface gravity, temperature and, in particular, for LTE versus non-LTE (NLTE), on me…
Molecular gas, dust, and star formation in galaxies. I. Dust properties and scalings in 1600 nearby galaxies
Magnelli, B.; Daddi, E.; Elbaz, D. +8 more
Context. Dust and its emission is increasingly being used to constrain the evolutionary stage of a galaxy. A comprehensive characterization of dust, best achieved in nearby bright galaxies, is thus a highly useful resource.
Aims: We aim to characterize the relationship between dust properties (mass, luminosity, and temperature) and their rela…
Analysis of a custom support vector machine for photometric redshift estimation and the inclusion of galaxy shape information
Singal, J.; Jones, E.
Aims: We present a custom support vector machine classification package for photometric redshift estimation, including comparisons with other methods. We also explore the efficacy of including galaxy shape information in redshift estimation. Support vector machines, a type of machine learning, utilize optimization theory and supervised learni…
Epoch of reionization 21 cm forecasting from MCMC-constrained semi-numerical models
Davé, Romeel; Finlator, Kristian; Hassan, Sultan +1 more
The recent low value of Planck Collaboration XLVII integrated optical depth to Thomson scattering suggests that the reionization occurred fairly suddenly, disfavouring extended reionization scenarios. This will have a significant impact on the 21 cm power spectrum. Using a semi-numerical framework, we improve our model from instantaneous to includ…
Analysis and modelling of recurrent solar flares observed with Hinode/EIS on March 9, 2012
Mason, H. E.; Del Zanna, G.; Pariat, E. +4 more
Three homologous C-class flares and one last M-class flare were observed by both the Solar Dynamics Observatory (SDO) and the Hinode EUV Imaging Spectrometer (EIS) in the AR 11429 on March 9, 2012. All the recurrent flares occurred within a short interval of time (less than 4 h), showed very similar plasma morphology and were all confined, until t…
HP2 survey. III. The California Molecular Cloud: A sleeping giant revisited
Alves, João; Lada, Charles J.; Lombardi, Marco +1 more
We present new high resolution and dynamic range dust column density and temperature maps of the California Molecular Cloud derived from a combination of Planck and Herschel dust-emission maps, and 2MASS NIR dust-extinction maps. We used these data to determine the ratio of the 2.2 µm extinction coefficient to the 850 µm opacity and fo…