Search Publications
Assessment of supervised machine learning for atmospheric retrieval of exoplanets
Madhusudhan, Nikku; Nixon, Matthew C.
Atmospheric retrieval of exoplanets from spectroscopic observations requires an extensive exploration of a highly degenerate and high-dimensional parameter space to accurately constrain atmospheric parameters. Retrieval methods commonly conduct Bayesian parameter estimation and statistical inference using sampling algorithms such as Markov chain M…
Asteroid masses obtained with INPOP planetary ephemerides
Fienga, A.; Avdellidou, C.; Hanuš, J.
In this paper, we present masses of 103 asteroids deduced from their perturbations on the orbits of the inner planets, in particular Mars and the Earth. These determinations and the INPOP19a planetary ephemerides are improved by the recent Mars orbiter navigation data and the updated orbit of Jupiter based on the Juno mission data. More realistic …
X-ray observations of luminous dusty quasars at z > 2
Fabian, A. C.; Lansbury, G. B.; Banerji, M. +1 more
We present new X-ray observations of luminous heavily dust-reddened quasars (HRQs) selected from infrared (IR) sky surveys. HRQs appear to be a dominant population at high redshifts and the highest luminosities, and may be associated with a transitional 'blowout' phase of black hole and galaxy co-evolution models. Despite this, their high-energy p…
The ALPINE-ALMA [C II] survey: a triple merger at z ∼ 4.56
Cimatti, A.; Maiolino, R.; Pozzi, F. +29 more
We report the detection of [C II] λ158 µm emission from a system of three closely separated sources in the Cosmic Evolution Survey (COSMOS) field at z ∼ 4.56 , as part of the Atacama Large Millimeter/submillimeter Array (ALMA) Large Program to INvestigate C II at Early times (ALPINE). The two most luminous sources are closely associated, bot…
Validating scattering-induced (sub)millimetre disc polarization through the spectral index, wavelength-dependent polarization pattern, and polarization spectrum: the case of HD 163296
Hull, Charles L. H.; Li, Zhi-Yun; Yang, Haifeng +3 more
A number of young circumstellar discs show strikingly ordered (sub)millimetre polarization orientations along the minor axis, which is strong evidence for polarization due to scattering by ∼0.1 mm-sized grains. To test this mechanism further, we model the ALMA dust continuum and polarization data of HD 163296 using radmc-3d. We find that scatterin…
Lyman continuum escape fraction in Ly α emitters at z ≃ 3.1
Fan, Xiaohui; Bian, Fuyan
We measure the Lyman continuum (LyC) escape fraction in 54 faint Lyman-alpha emitters (LAEs) at z ≃ 3.1 in the GOODS-South field. With the average magnitude of R = 26.7 AB (MUV = -18.8 and L ≃ 0.1L*), these galaxies represent a population of compact young dwarf galaxies. Their properties are likely to resemble those in the galaxies resp…
Probing the origin of low-frequency radio emission in PG quasars with the uGMRT - I
Ho, L. C.; Ishwara-Chandra, C. H.; Harrison, C. +3 more
We present the results from 685 MHz observations with the upgraded Giant Metrewave Radio Telescope (uGMRT) of 22 quasars belonging to the Palomar-Green (PG) quasar sample. Only four sources reveal extended radio structures on ∼10-30 kpc scales, while the rest are largely a combination of a radio core unresolved at the uGMRT resolution of ∼3-5 arcs…
An extended Pal 5 stream in Gaia DR2
Bovy, Jo; Webb, Jeremy J.; Starkman, Nathaniel
We present the results of a detailed search for members of the Pal 5 tidal tail system in Gaia Data Release 2 (DR2). Tidal tails provide a sensitive method for measuring the current and past gravitational potential of their host galaxy as well as for testing predictions for the abundance of dark matter subhaloes. The Pal 5 globular cluster and its…
Trimodal structure of Hercules stream explained by originating from bar resonances
Portegies Zwart, S.; Asano, Tetsuro; Fujii, M. S. +3 more
Gaia Data Release 2 revealed detailed structures of nearby stars in phase space. These include the Hercules stream, whose origin is still debated. Most of the previous numerical studies conjectured that the observed structures originate from orbits in resonance with the bar, based on static potential models for the Milky Way. We, in contrast, appr…
A Suzaku sample of unabsorbed narrow-line and broad-line Seyfert 1 galaxies - I. X-ray spectral properties
Gallo, L. C.; Waddell, S. G. H.
A sample of narrow-line Seyfert 1 (NLS1) and broad-line Seyfert 1 (BLS1) galaxies observed with Suzaku is presented. The final sample consists of 22 NLS1s and 47 BLS1s, for a total of 69 active galactic nuclei (AGNs) that are all at low redshift (z < 0.5) and exhibit low host-galaxy column densities (<1022 ${\rm cm}^{-2}\,$ ). The…