Search Publications
Quasar Sightline and Galaxy Evolution (QSAGE) - III. The mass-metallicity and fundamental metallicity relation of z ≈ 2.2 galaxies
Cullen, F.; Tejos, N.; Prochaska, J. X. +8 more
We present analysis of the mass-metallicity relation (MZR) for a sample of 67 [O III]-selected star-forming (SF) galaxies at a redshift range of z = 1.99-2.32 (zmed = 2.16) using Hubble Space Telescope Wide Field Camera 3 grism spectroscopy from the Quasar Sightline and Galaxy Evolution survey. Metallicities were determined using empiri…
Bulge+disc decomposition of HFF and CANDELS galaxies: UVJ diagrams and stellar mass-size relations of galaxy components at 0.2 ≤ z ≤ 1.5
Kartaltepe, Jeyhan S.; Koekemoer, Anton M.; Martis, Nicholas S. +13 more
Using deep imaging from the CANDELS and HFF surveys, we present bulge+disc decompositions with GALFITM for $\sim$17 000 galaxies over $0.2 \le z\le 1.5$. We use various model parameters to select reliable samples of discs and bulges, and derive their stellar masses using an empirically calibrated relation between mass-to-light ratio and colour. Ac…
Chemodynamical study of two CEMP-no stars from the Hamburg/ESO Survey
Shejeelammal, J.; Goswami, Aruna
The Carbon-Enhanced Metal-Poor (CEMP) stars with no enhancement of neutron-capture elements, the so-called CEMP-no stars are believed to be the direct descendants of first-generation stars and provide a unique opportunity to probe the early Galactic nucleosynthesis. We present a detailed chemical and kinematic analysis for two extremely metal-poor…
Impacts of the Local arm on the local circular velocity inferred from the Gaia DR3 young stars in the Milky Way
Seabroke, George; Kawata, Daisuke; Hunt, Jason A. S. +3 more
A simple one-dimensional axisymmetric disc model is applied to the kinematics of O type and B type stars (OB stars) near the Sun obtained from Gaia Data Release 3 catalogue. The model determines the 'local centrifugal speed' Vc(R0) - defined as the circular velocity in the Galactocentric rest frame, where the star would move …
The Hertzsprung progression of classical Cepheids in the Gaia era
Marconi, Marcella; Molinaro, Roberto; Ripepi, Vincenzo +6 more
A new fine grid of non-linear convective pulsation models for the so-called 'bump Cepheids' is presented to investigate the Hertzprung progression (HP) phenomenon shown by their light and radial pulsation velocity curves. The period corresponding to the centre of the HP is investigated as a function of various model assumptions, such as the effici…
Observing the galactic underworld: predicting photometry and astrometry from compact remnant microlensing events
Mérand, Antoine; Tuthill, Peter; Krone-Martins, Alberto +3 more
Isolated black holes (BHs) and neutron stars (NSs) are largely undetectable across the electromagnetic spectrum. For this reason, our only real prospect of observing these isolated compact remnants is via microlensing; a feat recently performed for the first time. However, characterization of the microlensing events caused by BHs and NSs is still …
Magnetic field at the Galactic centre from multiwavelength dust polarization
Hoang, Thiem; Akshaya, M. S.
We have mapped the magnetic field (B-field) for a region of about 30 pc around the centre of our Galaxy, which encompasses the circumnuclear disc (CND), the minispiral, and the 20 and 50 km s-1 molecular clouds, using thermal dust polarization observations obtained from SOFIA/HAWC+ and JCMT/SCUPOL. We decompose the spectra of 12
TOI-2490b - the most eccentric brown dwarf transiting in the brown dwarf desert
Trifonov, Trifon; Henning, Thomas; Ramsay, Gavin +40 more
We report the discovery of the most eccentric transiting brown dwarf in the brown dwarf desert, TOI-2490b. The brown dwarf desert is the lack of brown dwarfs around main-sequence stars within
Spectroscopic diagnostic of the footpoints of the cool loops
Dwivedi, B. N.; Kayshap, Pradeep; Jelínek, P. +2 more
Statistically, the cool loop's footpoints are diagnosed using Si IV resonance lines observations provided by Interface Region Imaging Spectrograph (IRIS). The intensity and full width at half-maximum (FWHM) of the loop's footpoints in β-γ active regions (ARs) are higher than the corresponding parameters of footpoints in β ARs. However, the Doppler…
Nature of 4FGL J1838.2+3223: A flaring 'spider' pulsar candidate
Zharikov, S. V.; Karpova, A. V.; Gilfanov, M. R. +4 more
An unidentified γ-ray source 4FGL J1838.2+3223 has been proposed as a pulsar candidate. We present optical time-series multiband photometry of its likely optical companion obtained with the 2.1-m telescope of Observatorio Astronómico Nacional San Pedro Mártir, Mexico. The observations and the data from the Zwicky Transient Facility revealed the so…