Search Publications
Stellar mass segregation as separating classifier between globular clusters and ultrafaint dwarf galaxies
Hilker, M.; Baumgardt, H.; Faller, J. +2 more
We have determined the amount of stellar mass segregation in over 50 globular clusters and ultrafaint dwarf galaxy candidates based on deep HST- and ground-based photometry. We find that the amount of mass segregation in globular clusters is strongly correlated with their relaxation time and that all clusters with relaxation times of the order of …
Identifying blue large amplitude pulsators from Gaia DR2 and ZTF DR3
Lam, Marco C.; McWhirter, Paul Ross
Blue large amplitude pulsators (BLAPs) are hot, subluminous stars undergoing rapid variability with periods of under 60 min. They have been linked with the early stages of pre-white dwarfs and hot subdwarfs. They are a rare class of variable star due to their evolutionary history within interacting binary systems and the short time-scales relative…
Blanco DECam Bulge Survey (BDBS) IV: Metallicity distributions and bulge structure from 2.6 million red clump stars
Clarkson, William I.; Rich, R. Michael; Kunder, Andrea +12 more
We present photometric metallicity measurements for a sample of 2.6 million bulge red clump stars extracted from the Blanco DECam Bulge Survey (BDBS). Similar to previous studies, we find that the bulge exhibits a strong vertical metallicity gradient, and that at least two peaks in the metallicity distribution functions appear at b < -5°. We ca…
Zodiacal exoplanets in time - XIII. Planet orbits and atmospheres in the V1298 Tau system, a keystone in studies of early planetary evolution
Kuzuhara, M.; Tamura, M.; Kudo, T. +16 more
Studies of planetary systems of stars in star-forming regions and young clusters open a window on the formative stages of planetary evolution. We obtained high-cadence high-resolution infrared spectroscopy of the solar-mass Taurus association-member V1298 Tau during a transit of its 10R⊕-size 'b' planet. We measured the systemic radial …
Kinematics beats dust: unveiling nested substructure in the perturbed outer disc of the Milky Way
Laporte, Chervin F. P.; Belokurov, Vasily; Koposov, Sergey E.
We use the Gaia eDR3 data and legacy spectroscopic surveys to map the Milky Way disc substructure towards the Galactic Anticentre at heliocentric distances $d\ge 10\, \rm {kpc}$. We report the discovery of multiple previously undetected new filaments embedded in the outer disc in highly extincted regions. Stars in these overdensities have distance…
Constraints on star formation in NGC 2264
Parker, Richard J.; Schoettler, Christina
We quantify the spatial distribution of stars for two subclusters centred around the massive/intermediate-mass stars S Mon and IRS 1/2 in the NGC 2264 star-forming region. We find that both subclusters have neither a substructured nor a centrally concentrated distribution according to the $\mathcal {Q}$-parameter. Neither subcluster displays mass …
A hot and luminous source at the site of the fast transient AT2018cow at 2-3 yr after its explosion
Sun, Ning-Chen; Crowther, Paul A.; Maund, Justyn R. +1 more
We report the discovery of a luminous late-time source at the position of the fast blue optical transient AT2018cow on images taken by the Hubble Space Telescope at 714 d and 1136 d after its explosion. This source is detected at both UV and optical wavelengths and has prominent Hα emission. It has a very stable brightness between the two epochs a…
Multiply lensed star forming clumps in the A521-sys1 galaxy at redshift 1
Richard, Johan; Adamo, Angela; Combes, Françoise +5 more
We study the population of star-forming clumps in A521-sys1, a $z=1.04$ system gravitationally lensed by the foreground ($z=0.25$) cluster Abell 0521. The galaxy presents one complete counter-image with a mean magnification of $\rm \mu \sim 4$ and a wide arc containing two partial images of A521-sys1 with magnifications reaching $\mu > 20$, all…
The building up of observed stellar scaling relations of massive galaxies and the connection to black hole growth in the TNG50 simulation
Faber, S. M.; Huertas-Company, M.; Dekel, A. +7 more
We study how mock-observed stellar morphological and structural properties of massive galaxies are built up between $z$ = 0.5 and $z$ = 3 in the TNG50 cosmological simulation. We generate mock images with the properties of the CANDELS survey and derive Sersic parameters and optical rest-frame morphologies as usually done in the observations. Overa…
Turning points in the age-metallicity relations - created by late satellite infall and enhanced by radial migration
Ness, Melissa K.; Buck, Tobias; Lu, Yuxi Lucy +1 more
The present-day age-metallicity relation (AMR) is a record of the star formation history of galaxies, as this traces the chemical enrichment of the gas over time. We use a zoomed-in cosmological simulation that reproduces key signatures of the Milky Way (MW), g2.79e12 from the NIHAO-UHD project, to examine how stellar migration and satellite infal…