Search Publications
Pointlike Sources among z > 11 Galaxy Candidates: Contaminants due to Supernovae at High Redshifts?
Yan, Haojing; Wang, Lifan; Ma, Zhiyuan +1 more
The recent searches for z > 11 galaxies using the James Webb Space Telescope have resulted in an unexpectedly high number of candidate objects, which imply at least 1 order of magnitude higher number density of z > 11 galaxies than the previously favored predictions. A question has risen whether there are some new types of contaminants among…
Minute-cadence observations of the LAMOST fields with the TMTS - III. Statistical study of the flare stars from the first two years
Shi, Jianrong; Wang, Xiaofeng; Mo, Jun +22 more
Tsinghua University-Ma Huateng Telescopes for Survey (TMTS) aims to detect fast-evolving transients in the Universe, which has led to the discovery of thousands of short-period variables and eclipsing binaries since 2020. In this paper, we present the observed properties of 125 flare stars identified by TMTS within the first two years, with an att…
Occurrence Rates of Electromagnetic Ion Cyclotron (EMIC) Waves With Rising Tones in the Van Allen Probes Data Set
Smith, C. W.; Kletzing, C. A.; Sigsbee, K. +1 more
In Fourier time-frequency power spectrograms of satellite magnetic field data, electromagnetic ion cyclotron (EMIC) waves may feature discrete, rising tone structures that rapidly increase in frequency. Using data from the Van Allen Probes Electric and Magnetic Field Instrument Suite and Integrated Science (EMFISIS) fluxgate magnetometer, we condu…
OH mid-infrared emission as a diagnostic of H2O UV photodissociation. II. Application to interstellar photodissociation regions
Le Petit, F.; van Dishoeck, E. F.; Bron, E. +3 more
Context. Water photodissociation in the 114-143 nm UV range forms excited OH which emits at mid-infrared (MIR) wavelengths via highly excited rotational lines. These lines have only been detected with Spitzer in proto-planetary disks and shocks. Previous studies have shown that they are a unique diagnostic for water photodissociation. Thanks to it…
Chemodynamical properties and ages of metal-poor stars in S-PLUS
Mendes de Oliveira, C.; Placco, V. M.; Beraldo e Silva, L. +10 more
Metal-poor stars are key to our understanding of the early stages of chemical evolution in the Universe. New multifilter surveys, such as the Southern Photometric Local Universe Survey (S-PLUS), are greatly advancing our ability to select low-metallicity stars. In this work, we analyse the chemodynamical properties and ages of 522 metal-poor candi…
On the origin of optical and IR emission lines in star-forming galaxies
Bruzual, Gustavo; Martínez-Paredes, Mariela; Morisset, Christophe +3 more
Combining the CLOUDY photoionization code with updated stellar population synthesis results, we simultaneously model the MIR $\rm{[Ne {}{\small III}]}/\rm{[Ne {}{\small II}]}$ versus $\rm{[O {}{\small IV}]}/\rm{[Ne {}{\small III}]}$, the MIR-FIR $\rm{[Ne {}{\small III}]}/\rm{[Ne {}{\small II}]}$ versus $\rm{[O {}{\small IV}]}/\rm{[O {}{\small III}…
A benchmark study of atomic models for the transition region against quiet Sun observations
Mason, H. E.; Del Zanna, G.; Dufresne, R. P.
The use of the coronal approximation to model line emission from the solar transition region has led to discrepancies with observations over many years, particularly for Li- and Na-like ions. Studies have shown that a number of atomic processes are required to improve the modelling for this region, including the effects of high densities, solar ra…
Dust from evolved stars: a pilot analysis of the AGB to PN transition
Bianchi, S.; Dell'Agli, F.; Ventura, P. +5 more
We present a novel approach to address dust production by low- and intermediate-mass stars. We study the asymptotic giant branch (AGB) phase, during which the formation of dust takes place, from the perspective of post-AGB and planetary nebula (PN) evolutionary stage. Using results from stellar evolution and dust formation modelling, we interpret …
The evolution of our understanding of coronal mass ejections
Vourlidas, Angelos; Stenborg, Guillermo; Howard, Russell A.
The unexpected observation of a sudden expulsion of mass through the solar corona in 1971 opened up a new field of interest in solar and stellar physics. The discovery came from a white-light coronagraph, which creates an artificial eclipse of the Sun, enabling the viewing of the faint glow from the corona. This observation was followed by many mo…
Coronal X-Ray Emission from Nearby, Low-mass, Exoplanet Host Stars Observed by the MUSCLES and Mega-MUSCLES HST Treasury Survey Projects
Loyd, R. O. Parke; Kowalski, Adam F.; Brown, Alexander +8 more
The high-energy X-ray and ultraviolet (UV) radiation fields of exoplanet host stars play a crucial role in controlling the atmospheric conditions and the potential habitability of exoplanets. Major surveys of the X-ray/UV emissions from late-type (K and M spectral types) exoplanet hosts have been conducted by the Measurements of the Ultraviolet Sp…