arXiv subjects

Carole Haswell

Publications and source records attributed to Carole Haswell.

3 recordsLinked to original sources

arXiv2025

Transformational astrophysics and exoplanet science with Habitable Worlds Observatory's High Resolution Imager

Habitable Worlds Observatory (HWO) will be NASA's flagship space telescope of the 2040s, designed to search for life on other planets and to transform broad areas of astrophysics. NASA are seeking international partners, and the UK is well-placed to lead the design and construction of its imaging camera - which is likely to produce the mission's most visible public impact. Early participation in the mission would return investment to UK industry, and bring generational leadership for the UK in space science, space technology, and astrophysics.

astro-ph.IM↗

arXiv2021

Ariel: Enabling planetary science across light-years

Ariel, the Atmospheric Remote-sensing Infrared Exoplanet Large-survey, was adopted as the fourth medium-class mission in ESA's Cosmic Vision programme to be launched in 2029. During its 4-year mission, Ariel will study what exoplanets are made of, how they formed and how they evolve, by surveying a diverse sample of about 1000 extrasolar planets, simultaneously in visible and infrared wavelengths. It is the first mission dedicated to measuring the chemical composition and thermal structures of hundreds of transiting exoplanets, enabling planetary science far beyond the boundaries of the Solar System. The payload consists of an off-axis Cassegrain telescope (primary mirror 1100 mm x 730 mm ellipse) and two separate instruments (FGS and AIRS) covering simultaneously 0.5-7.8 micron spectral range. The satellite is best placed into an L2 orbit to maximise the thermal stability and the field of regard. The payload module is passively cooled via a series of V-Groove radiators; the detectors for the AIRS are the only items that require active cooling via an active Ne JT cooler. The Ariel payload is developed by a consortium of more than 50 institutes from 16 ESA countries, which include the UK, France, Italy, Belgium, Poland, Spain, Austria, Denmark, Ireland, Portugal, Czech Republic, Hungary, the Netherlands, Sweden, Norway, Estonia, and a NASA contribution.

astro-ph.IM↗

arXiv2011

A Compact Degenerate Primary-Star Progenitor of SN 2011fe

While a white dwarf is, from a theoretical perspective, the most plausible primary star in Type Ia supernova (SN Ia), many other candidates have not been formally ruled out. Shock energy deposited in the envelope of any exploding primary contributes to the early SN brightness and, since this radiation energy is degraded by expansion after the explosion, the diffusive luminosity depends on the initial primary radius. We present a new non-detection limit of the nearby SN Ia 2011fe, obtained what appears to be just 4 hours after explosion, allowing us to directly constrain the initial primary radius, R_p. Coupled with the non-detection of a quiescent X-ray counterpart and the inferred synthesized Ni mass, we show that R_p <~ 0.02 R_sun (a factor of 5 smaller than previously inferred), that the average density of the primary must be rho_p > 10,000 gm cm^{-3}, and that the effective temperature must be less than a few x 10^5 K. This rules out hydrogen burning main sequence stars and giants. Constructing the helium-burning main sequence and carbon-burning main sequence, we find such objects are also excluded. By process of elimination, we find that only degeneracy-supported compact objects---WDs and neutron stars---are viable as the primary star of SN 2011fe. With few caveats, we also restrict the companion (secondary) star radius to R_ c <~ 0.1 R_sun, excluding Roche-Lobe overflowing red giant and main-sequence companions to high significance.

astro-ph.HE↗