Search Publications
VINTERGATAN-GM: The cosmological imprints of early mergers on Milky-Way-mass galaxies
Feuillet, Diane K.; Martin, Nicolas F.; Pontzen, Andrew +6 more
We present a new suite of cosmological zoom-in hydrodynamical ($\approx 20\, \mathrm{pc}$ spatial resolution) simulations of Milky-Way mass galaxies to study how a varying mass ratio for a Gaia-Sausage-Enceladus (GSE) progenitor impacts the z = 0 chemodynamics of halo stars. Using the genetic modification approach, we create five cosmological hist…
An ever-present Gaia snail shell triggered by a dark matter wake
Grand, Robert J. J.; Gómez, Facundo A.; van de Voort, Freeke +5 more
We utilize a novel numerical technique to model star formation in cosmological simulations of galaxy formation - called SUPERSTARS - to simulate a Milky Way-like galaxy with ≳108 star particles to study the formation and evolution of out-of-equilibrium stellar disc structures in a full cosmological setting. In the plane defined by the c…
Planet engulfment detections are rare according to observations and stellar modelling
Berger, Travis A.; Howard, Andrew W.; Behmard, Aida +2 more
Dynamical evolution within planetary systems can cause planets to be engulfed by their host stars. Following engulfment, the stellar photosphere abundance pattern will reflect accretion of rocky material from planets. Multistar systems are excellent environments to search for such abundance trends because stellar companions form from the same nata…
A search for compact object companions to high mass function single-lined spectroscopic binaries in Gaia DR3
Kochanek, C. S.; Stanek, K. Z.; Thompson, Todd A. +2 more
Gaia Data Release 3 (DR3) provides >181 000 radial velocity (RV) solutions for single-lined spectroscopic binaries (SB1s) that can be used to search for non-interacting compact object + star binary candidates by selecting systems with large mass functions. We selected 234 such systems and identified 115 systems with good RV solutions in DR3. We…
A prescription for the asteroseismic surface correction
Li, Yaguang; Huber, Daniel; Bedding, Timothy R. +11 more
In asteroseismology, the surface effect refers to a disparity between the observed and the modelled frequencies in stars with solar-like oscillations. It originates from improper modelling of the surface layers. Correcting the surface effect usually requires using functions with free parameters, which are conventionally fitted to the observed freq…
Cepheid Metallicity in the Leavitt Law (C- MetaLL) survey - II. High-resolution spectroscopy of the most metal poor Galactic Cepheids
Ripepi, V.; Marconi, M.; Musella, I. +5 more
Classical Cepheids (DCEPs) are the first fundamental step in the calibration of the cosmological distance ladder. Furthermore, they represent powerful tracers in the context of Galactic studies. We have collected high-resolution spectroscopy with UVES@VLT for a sample of 65 DCEPs. The majority of them are the faintest DCEPs ever observed in the Mi…
A BayeSN distance ladder: H0 from a consistent modelling of Type Ia supernovae from the optical to the near-infrared
Narayan, Gautham; Jha, Saurabh W.; Dhawan, Suhail +4 more
The local distance ladder estimate of the Hubble constant (H0) is important in cosmology, given the recent tension with the early universe inference. We estimate H0 from the Type Ia supernova (SN Ia) distance ladder, inferring SN Ia distances with the hierarchical Bayesian SED model, BayeSN. This method has a notable advantag…
AGNs in post-mergers from the ultraviolet near infrared optical northern survey
Ellison, Sara L.; Bickley, Robert W.; Patton, David R. +1 more
The kinematic disturbances associated with major galaxy mergers are known to produce gas inflows, which in turn may trigger accretion onto the supermassive black holes (SMBH) of the participant galaxies. While this effect has been studied in galaxy pairs, the frequency of active galactic nuclei (AGNs) in fully coalesced post-merger systems is poor…
Bright extragalactic ALMA redshift survey (BEARS) III: detailed study of emission lines from 71 Herschel targets
Berta, S.; Ivison, R. J.; Omont, A. +55 more
We analyse the molecular and atomic emission lines of 71 bright Herschel-selected galaxies between redshifts 1.4 and 4.6 detected by the Atacama Large Millimeter/submillimeter Array. These lines include a total of 156 CO, [C I], and H2O emission lines. For 46 galaxies, we detect two transitions of CO lines, and for these galaxies we fin…
Hunting for C-rich long-period variable stars in the Milky Way's bar-bulge using unsupervised classification of Gaia BP/RP spectra
Matsunaga, Noriyuki; Sanders, Jason L.
The separation of oxygen- and carbon-rich asymptotic giant branch sources is crucial for their accurate use as local and cosmological distance and age/metallicity indicators. We investigate the use of unsupervised learning algorithms for classifying the chemistry of long-period variables from Gaia DR3's BP/RP spectra. Even in the presence of signi…