Search Publications
New constraints on the HR 8799 planetary system from mid-infrared direct imaging
Fedele, D.; Kissler-Patig, M.; van den Ancker, M. E. +2 more
Direct imaging is a tried and tested method of detecting exoplanets in the near-infrared (IR), but has so far not been extended to longer wavelengths. New data at mid-IR wavelengths (8-20 µm) can provide additional constraints on planetary atmospheric models. We use the VLT Imager and Spectrometer for the mid-IR (VISIR) instrument on the VLT…
A detailed study on the reflection component for the black hole candidate MAXI J1836-194
Gou, Lijun; García, Javier A.; Liu, Zhu +3 more
We present a detailed spectral analysis of the black hole candidate MAXI J1836-194. The source was caught in the intermediate state during its 2011 outburst by Suzaku and RXTE. We jointly fit the X-ray data from these two missions using the relxill model to study the reflection component, and a steep inner emissivity profile indicating a compact c…
Host galaxy properties and environment of obscured and unobscured X-ray selected active galactic nuclei in the COSMOS survey
Bornancini, C.; García Lambas, D.
We analyse different photometric and spectroscopic properties of active galactic nuclei (AGNs) and quasars (QSOs) selected by their mid-IR power-law and X-ray emission from the COSMOS survey. We use a set of star-forming galaxies as a control sample to compare with the results. We have considered samples of obscured (HR > -0.2) and unobscured (…
The globular cluster M10: reassessment of stellar membership, distance, and age using its variable and HB stars
Arellano Ferro, A.; Calderón, J. H.; Muneer, S. +4 more
Time-series VI CCD photometry of the globular cluster M10 (NGC 6254) is employed to perform a detailed identification, inspection of their light curves, their classification, and their cluster membership, of all the known variables reported up to 2018. The membership analysis is based on the $Gaia$ -DR2 positions and proper motions. The metallicit…
The properties of radio and mid-infrared detected galaxies and the effect of environment on the co-evolution of AGN and star formation at z ∼ 1
Shen, Lu; Wu, Po-Feng; Fassnacht, Christopher D. +10 more
In this study, we investigate 179 radio-infrared (IR) galaxies drawn from a sample of spectroscopically confirmed galaxies, which are detected in radio and mid-IR (MIR) in the redshift range of 0.55 ≤ z ≤ 1.30 in the Observations of Redshift Evolution in Large Scale Environments (ORELSE) survey. We constrain the active galactic nuclei (AGN) contri…
Distance mapping applied to four well-known planetary nebulae and a nova shell
Gonçalves, Denise R.; Akras, Stavros; Steffen, Wolfgang +1 more
Accurate distance estimates of astrophysical objects such as planetary nebulae (PNe), and nova and supernova remnants, among others, allow us to constrain their physical characteristics, such as size, mass, luminosity, and age. An innovative technique based on the expansion parallax method, the so-called distance mapping technique (DMT), provides …
A single galaxy population? Statistical evidence that the star-forming main sequence might be the tip of the iceberg
Ascasibar, Y.; López-Sánchez, Á. R.; Corcho-Caballero, P.
According to their specific star formation rate (sSFR), galaxies are often divided into 'star-forming' and 'passive' populations. It is argued that the former define a narrow 'main sequence of star-forming galaxies' (MSSF) of the form sSFR(M*), whereas 'passive' galaxies feature negligible levels of star formation activity. Here we use …
The stringent upper limit on jet power in the persistent soft-state source 4U 1957+11
Maccarone, Thomas J.; McHardy, Ian M.; Miller-Jones, James C. A. +5 more
We present extremely deep upper limits on the radio emission from 4U 1957+11, an X-ray binary that is generally believed to be a persistently accreting black hole that is almost always in the soft state. We discuss a more comprehensive search for Type I bursts than in past work, revealing a stringent upper limit on the burst rate, bolstering the c…
K2 observations of the pulsating subdwarf B stars UY Sex and V1405 Ori
Reed, M. D.; Jeffery, C. S.; Baran, A. S. +5 more
We processed and analysed K2 observations of the pulsating subdwarf-B (sdBV) stars UY Sex and V1405 Ori. We detect 97 p-mode pulsations in UY Sex while we discover V1405 Ori to be a rare rich hybrid pulsator with over 100 p-mode pulsations and 19 g-mode pulsations. We detect frequency multiplets, which we use to identify pulsation modes as well as…
High-amplitude γ Doradus variables
Paunzen, Ernst; Hambsch, Franz-Josef; Hümmerich, Stefan +3 more
According to most literature sources, the amplitude of the pulsational variability observed in γ Doradus stars does not exceed 0.1 mag in Johnson V. We have analysed fifteen high-amplitude γ Doradus stars with photometric peak-to-peak amplitudes well beyond this limit, with the aim of unraveling the mechanisms behind the observed high amplitudes a…