Search Publications
Substructure in the stellar halo near the Sun. I. Data-driven clustering in integrals-of-motion space
Koppelman, H. H.; Helmi, A.; Ruiz-Lara, T. +3 more
Context. Merger debris is expected to populate the stellar haloes of galaxies. In the case of the Milky Way, this debris should be apparent as clumps in a space defined by the orbital integrals of motion of the stars.
Aims: Our aim is to develop a data-driven and statistics-based method for finding these clumps in integrals-of-motion space fo…
Direct-imaging Discovery and Dynamical Mass of a Substellar Companion Orbiting an Accelerating Hyades Sun-like Star with SCExAO/CHARIS
Currie, Thayne; Kwon, Jungmi; Tamura, Motohide +33 more
We present the direct-imaging discovery of a substellar companion in orbit around a Sun-like star member of the Hyades open cluster. So far, no other substellar companions have been unambiguously confirmed via direct imaging around main-sequence stars in Hyades. The star HIP 21152 is an accelerating star as identified by the astrometry from the Ga…
Testing gravity on cosmic scales: A case study of Jordan-Brans-Dicke theory
Joudaki, Shahab; Ferreira, Pedro G.; Lima, Nelson A. +1 more
We provide an end-to-end exploration of a distinct modified gravitational theory in Jordan-Brans-Dicke (JBD) gravity, from an analytical and numerical description of the background expansion and linear perturbations, to the nonlinear regime captured with a hybrid suite of N -body simulations, to the cosmological constraints from existing probes of…
Low-power jet-interstellar medium interaction in NGC 7319 revealed by JWST/MIRI MRS
Colina, L.; Hönig, S. F.; García-Burillo, S. +8 more
We present JWST/MIRI MRS spectroscopy of NGC 7319, the largest galaxy in the Stephan's Quintet, observed as part of the Early Release Observations (ERO). NGC 7319 hosts a type 2 active galactic nucleus (AGN) and a low-power radio jet (L1.4 GHz = 3.3 × 1022 W Hz−1) with two asymmetric radio hotspots at 430 pc (N2) a…
The first ground-level enhancement of solar cycle 25 on 28 October 2021
Usoskin, I.; Vainio, R.; Gieseler, J. +8 more
Aims: The first relativistic solar proton event of solar cycle 25 was detected on 28 October 2021 by neutron monitors (NMs) on the ground and particle detectors on board spacecraft in near-Earth space. This is the first ground-level enhancement (GLE) of the current cycle. A detailed reconstruction of the NM response together with the identifi…
GOODS-ALMA 2.0: Starbursts in the main sequence reveal compact star formation regulating galaxy evolution prequenching
Magnelli, B.; Daddi, E.; Elbaz, D. +38 more
Compact star formation appears to be generally common in dusty star-forming galaxies (SFGs). However, its role in the framework set by the scaling relations in galaxy evolution remains to be understood. In this work we follow up on the galaxy sample from the GOODS-ALMA 2.0 survey, an ALMA blind survey at 1.1 mm covering a continuous area of 72.42 …
A New Estimate of the Cosmic Star Formation Density from a Radio-selected Sample, and the Contribution of H-dark Galaxies at z ≥ 3
Bisigello, Laura; Pozzi, Francesca; Calura, Francesco +13 more
The star formation rate density (SFRD) history of the universe is well constrained up to redshift z ~ 2. At earlier cosmic epochs, the picture has been largely inferred from UV-selected galaxies (e.g., Lyman-break galaxies; LBGs). However, the inferred star formation rates of LBGs strongly depend on the assumed dust extinction correction, which is…
A Census of the Stellar Populations in the Sco-Cen Complex
Luhman, K. L.
I have used high-precision photometry and astrometry from the early installment of the third data release of Gaia (EDR3) to perform a survey for members of the stellar populations within the Sco-Cen complex, which consist of Upper Sco, UCL/LCC, the V1062 Sco group, Ophiuchus, and Lupus. Among Gaia sources with σ π < 1 mas, I have i…
ExoMiner: A Highly Accurate and Explainable Deep Learning Classifier That Validates 301 New Exoplanets
Jenkins, Jon M.; Caldwell, Douglas A.; Twicken, Joseph D. +10 more
The Kepler and Transiting Exoplanet Survey Satellite (TESS) missions have generated over 100,000 potential transit signals that must be processed in order to create a catalog of planet candidates. During the past few years, there has been a growing interest in using machine learning to analyze these data in search of new exoplanets. Different from…
Constraining the original composition of the gas forming first-generation stars in globular clusters
Milone, A. P.; Cordoni, G.; Marino, A. F. +13 more
Disentangling distinct stellar populations along the red-giant branches (RGBs) of globular clusters (GCs) is possible by using the pseudo-two-colour diagram dubbed chromosome map (ChM). One of the most intriguing findings is that the so-called first-generation (1G) stars, characterized by the same chemical composition of their natal cloud, exhibit…