Search Publications
Spectroscopic study of solar transition region oscillations in the quiet-Sun observed by IRIS using the Si IV spectral line
Srivastava, A. K.; Wang, T. J.; Kayshap, P. +3 more
In this paper, we use the Si IV 1393.755 Å spectral line observed by the Interface Region Imaging Spectrograph (IRIS) in the quiet-Sun (QS) to determine the physical nature of the solar transition region (TR) oscillations. We analyse the properties of these oscillations using wavelet tools (e.g. power, cross-power, coherence, and phase difference)…
The neutron-capture and α-elements abundance ratios scatter in old stellar populations: cosmological simulations of the stellar halo
Chiappini, Cristina; Cescutti, Gabriele; Scannapieco, Cecilia
We investigate the origin of the abundance ratios and scatter of the neutron-capture elements Sr, Ba, and Eu in the stellar halo of a Milky Way-mass galaxy formed in a hydrodynamical cosmological simulation, and compare them with those of α elements. For this, we implement a novel treatment for chemical enrichment of Type II supernovae that consid…
The recent star formation history of NGC 628 on resolved scales
Saintonge, Amélie; De Looze, Ilse; Decleir, Marjorie +1 more
Star formation histories (SFHs) are integral to our understanding of galaxy evolution. We can study recent SFHs by comparing the star formation rate (SFR) calculated using different tracers, as each probes a different time-scale. We aim to calibrate a proxy for the present-day rate of change in SFR, dSFR/dt, which does not require full spectral en…
The Cluster Ages Experiment (CASE) - IX. Analysis of four detached eclipsing binaries in the globular cluster NGC 3201
Marshall, J. L.; Thompson, I. B.; Morrell, N. +14 more
We use photometric and spectroscopic observations of four detached eclipsing binaries in the globular cluster NGC 3201 to derive masses, radii, and luminosities of the component stars. Spanning across almost three magnitudes in the colour-magnitude diagram, the components offer a unique possibility to test the theory of stellar evolution. Their ma…
Detached eclipsing binaries from the Kepler field: radii and photometric masses of components in short-period systems
Diaz, Marcos P.; Cruz, Patricia; Aguilar, John F. +2 more
The characterization of detached eclipsing binaries with low-mass components has become important when verifying the role of convection in stellar evolutionary models, which requires model-independent measurements of stellar parameters with great precision. However, spectroscopic characterization depends on single-target radial velocity observatio…
The galaxy population of the core of the Coma cluster
Hasan, S. N.; Poloji, Nagamani; Hasan, Priya
In this paper, we present the structural properties and morphology of galaxies in the central region of the Coma Cluster brighter than 19.5 mag in the F814W band from the HST/ACS Coma Cluster Treasury Survey. Using mainly spectroscopic redshifts, we find 132 members from our sample of 219 galaxies. In our sample of 132 members, we find 51 non-dwar…
Seismic modelling of the pulsating mercury-manganese star HD 29589
Niemczura, E.; Hubrig, S.; Hummel, C. A. +4 more
Photometric and spectroscopic time-series of chemically peculiar mercury-manganese (HgMn) stars show variability, which in most cases is interpreted as the effect of binarity or surface spots. Until recently, pulsations have not been detected in these objects. However, the analysis of the Transiting Exoplanet Survey Satellite (TESS) photometric ti…
Dust extinction map of the Galactic plane based on the VVV survey data
Zhang, M.; Kainulainen, J.
Dust extinction is one of the most reliable tracers of the gas distribution in the Milky Way. The near-infrared (NIR) Vista Variables in the Vía Láctea (VVV) survey enables extinction mapping based on stellar photometry over a large area in the Galactic plane. We devise a novel extinction mapping approach, XPNICER, by bringing together VVV photome…
Completing the protostellar luminosity function in Cygnus-X with SOFIA/FORCAST imaging
Gutermuth, Robert A.; Pokhrel, Riwaj; Heyer, Mark +4 more
We present a new SOFIA/FORCAST mid-infrared survey of luminous protostars and crowded star-forming environments in Cygnus X, the nearest million-solar mass molecular cloud complex. We derive bolometric luminosities for over 1000 sources in the region with these new data in combination with extant Spitzer and UKIDSS photometry, with 63 new luminous…
The strongly irradiated planets in Praesepe
Wheatley, Peter J.; Agüeros, Marcel A.; King, George W. +3 more
We present an analysis of XMM-Newton observations of four stars in the young (670 Myr) open cluster Praesepe. The planets hosted by these stars all lie close in radius-period space to the radius-period valley and/or the Neptunian desert, two features that photoevaporation by X-ray and extreme ultraviolet (EUV) photons could be driving. Although th…