Search Publications
Chemical tracers of a highly eccentric AGB-main-sequence star binary
Menten, K. M.; Pinte, C.; Sahai, R. +32 more
Binary interactions have been proposed to explain a variety of circumstellar structures seen around evolved stars, including asymptotic giant branch (AGB) stars and planetary nebulae. Studies resolving the circumstellar envelopes of AGB stars have revealed spirals, disks and bipolar outflows, with shaping attributed to interactions with a companio…
Detection of the elusive dangling OH ice features at ~2.7 µm in Chamaeleon I with JWST NIRCam
Sun, F.; Egami, E.; Rocha, W. R. M. +31 more
Ascertaining the morphology and composition of the icy mantles covering dust grains in dense, cold regions of the interstellar medium is essential to developing accurate astrochemical models, determining conditions for ice formation, constraining chemical interactions in and on icy grains and understanding how ices withstand space radiation. The w…
Galactic Chemical Evolution Models Favor an Extended Type Ia Supernova Delay-time Distribution
Johnson, Jennifer A.; Johnson, James W.; Dubay, Liam O.
Type Ia supernovae (SNe Ia) produce most of the Fe-peak elements in the Universe and therefore are a crucial ingredient in galactic chemical evolution models. SNe Ia do not explode immediately after star formation, and the delay-time distribution (DTD) has not been definitively determined by supernova surveys or theoretical models. Because the DTD…
Unveiling δ Scuti and γ Doradus hybrid pulsation of HD 53166 and HD 53349 plus rich frequencies in HD 52788
Zhou, Ai-Ying
We present discoveries of the hybrid δ Scuti and γ Doradus types stellar pulsational variability of two stars, HD 53166 and HD 53349, which were previously used as comparison in the differential photometry of a known δ Scuti star HD 52788. More surprisingly, HD 52788 exhibits 126 pulsation frequencies in a small domain in 4-12 d-1 based…
ReveaLLAGN 0: First Look at JWST MIRI Data of Sombrero and NGC 1052
Kirkpatrick, Allison; Trump, Jonathan R.; Lützgendorf, Nora +28 more
We present the first results from the Revealing Low-Luminosity Active Galactic Nuclei (ReveaLLAGN) survey, a JWST survey of seven nearby LLAGNs. We focus on two observations with the Mid-Infrared Instrument (MIRI)'s Medium-Resolution Spectrometer of the nuclei of NGC 1052 and Sombrero (NGC 4594/M104). We also compare these data to public JWST data…
Uniting Gaia and APOGEE to unveil the cosmic chemistry of the Milky Way disc
Casey, Andrew R.; Rix, Hans-Walter; Brown, Anthony G. A. +6 more
The spatial distribution of Galactic stars with different chemical abundances encodes information on the processes that drove the formation and evolution of the Milky Way. Survey selection functions are indispensable for analysing astronomical catalogues produced by large-scale surveys. The use of these selection functions in data modelling is mor…
Lyα Emission Line Profiles of Extreme [O III]- emitting Galaxies at z ≳ 2: Implications for Lyα Visibility in the Reionization Era
Tang, Mengtao; Stark, Daniel P.; Ellis, Richard S. +4 more
JWST observations have recently begun delivering the first samples of Lyα velocity profile measurements at z > 6, opening a new window into the reionization process. Interpretation of z ≳ 6 line profiles is currently stunted by limitations in our knowledge of the intrinsic Lyα profile (before encountering the intergalactic medium (IGM)) of the …
Dust mineralogy and variability of the inner PDS 70 disk: Insights from JWST/MIRI MRS and Spitzer IRS observations
Henning, Thomas; Güdel, Manuel; Lagage, Pierre-Olivier +17 more
Context. The inner disk of the young star PDS 70 may be a site of rocky planet formation, with two giant planets detected further out. Recently, James Webb Space Telescope/Mid-Infrared Instrument (JWST/MIRI) Medium-Resolution Spectrometer (MRS) observations have revealed the presence of warm water vapour in the inner disk. Solids in the inner disk…
The Scavenger Hunt for Quasar Samples to Be Used as Cosmological Tools
Bargiacchi, Giada; Dainotti, Maria Giovanna; Lenart, Aleksander Łukasz +1 more
Although the Λ Cold Dark Matter model is the most accredited cosmological model, information at high redshifts (z) between type Ia supernovae (z=2.26) and the Cosmic Microwave Background (z=1100) is crucial to validate this model further. To this end, we have discovered a sample of 1132 quasars up to z=7.54 exhibiting a reduced intrinsic dispersio…
Ultradeep ATCA Imaging of 47 Tucanae Reveals a Central Compact Radio Source
Kamann, Sebastian; Dreizler, Stefan; Strader, Jay +9 more
We present the results of an ultradeep radio continuum survey, containing ~480 hr of observations, of the Galactic globular cluster 47 Tucanae with the Australia Telescope Compact Array. This comprehensive coverage of the cluster allows us to reach rms noise levels of 1.19 µJy beam-1 at 5.5 GHz, 940 nJy beam-1 at 9 GHz,…