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Calibration at elevation of the WEAVE fibre positioner

Ground-based and Airborne Instrumentation for Astronomy IX Proc. SPIE 12184 (2022) 121846J

Authors:

Sarah Hughes, Gavin Dalton, Kevin Dee, Don Carlos Abrams, Kevin Middleton, Ian Lewis, David Terrett, Alfonso L. Aguerri, Marc Balcells, Georgia Bishop, Piercarlo Bonifacio, Esperanza Carrasco, Scott Trager, Antonella Vallenari

Abstract:

WEAVE is the new wide-field spectroscopy facility for the prime focus of the William Herschel Telescope in La Palma, Spain. Its fibre positioner is essential for the accurate placement of the spectrograph's 960 fibre multiplex. We provide an overview of the recent maintenance, flexure modifications, and calibration measurements conducted at the observatory prior to the final top-end assembly. This work ensures that we have a complete understanding of the positioner's behaviour as it changes orientation during observations. All fibre systems have been inspected and repaired, and the tumbler structure contains new clamps to stiffen both the internal beam and the retractor support disk onto which the field plates attach. We present the updated metrology procedures and results that will be verified on-sky.
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Dust in and towards the Galactic Centre

Dust in planetary nebulae

IAU Symposium No. 131

Dynamical modeling of SAURON galaxies

Proceedings of IUTAM Symposia and Summer Schools IUTAM 3

Authors:

Michele Cappellari, RCEVD Bosch, EK Verolme, R Bacon, Martin Bureau, Y Copin, RL Davies, E Emsellem, D Krajnovic, H Kuntschner, R McDermid, BW Miller, RF Peletier, PTD Zeeuw

Abstract:

We describe our program for the dynamical modeling of early-type galaxies observed with the panoramic integral-field spectrograph SAURON. We are using Schwarzschild's numerical orbit superposition method to reproduce in detail all kinematical and photometric observables, and recover the intrinsic orbital structure of the galaxies. Since catastrophes are the most prominent features in the orbital observables, two-dimensional kinematical coverage is essential to constrain the dynamical models.

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First Detection of Spectral Variations of Anomalous Microwave Emission with QUIJOTE and C-BASS

Authors:

R Cepeda-Arroita, S Harper, C Dickinson, Ja Rubiño-Martín, Rt Génova-Santos, Angela C Taylor, Tj Pearson, M Ashdown, A Barr, Rb Barreiro, B Casaponsa, Fj Casas, Hc Chiang, R Fernandez-Cobos, Rdp Grumitt, F Guidi, Hm Heilgendorff, D Herranz, Lrp Jew, Jl Jonas, Michael E Jones, A Lasenby, J Leech, Jp Leahy, E Martínez-González, Mw Peel, F Poidevin, L Piccirillo, Acs Readhead, R Rebolo, B Ruiz-Granados, J Sievers, F Vansyngel, P Vielva, Ra Watson

Abstract:

Anomalous Microwave Emission (AME) is a significant component of Galactic diffuse emission in the frequency range $10$-$60\,$GHz and a new window into the properties of sub-nanometre-sized grains in the interstellar medium. We investigate the morphology of AME in the $\approx10^{\circ}$ diameter $\lambda$ Orionis ring by combining intensity data from the QUIJOTE experiment at $11$, $13$, $17$ and $19\,$GHz and the C-Band All Sky Survey (C-BASS) at $4.76\,$GHz, together with 19 ancillary datasets between $1.42$ and $3000\,$GHz. Maps of physical parameters at $1^{\circ}$ resolution are produced through Markov Chain Monte Carlo (MCMC) fits of spectral energy distributions (SEDs), approximating the AME component with a log-normal distribution. AME is detected in excess of $20\,\sigma$ at degree-scales around the entirety of the ring along photodissociation regions (PDRs), with three primary bright regions containing dark clouds. A radial decrease is observed in the AME peak frequency from $\approx35\,$GHz near the free-free region to $\approx21\,$GHz in the outer regions of the ring, which is the first detection of AME spectral variations across a single region. A strong correlation between AME peak frequency, emission measure and dust temperature is an indication for the dependence of the AME peak frequency on the local radiation field. The AME amplitude normalised by the optical depth is also strongly correlated with the radiation field, giving an overall picture consistent with spinning dust where the local radiation field plays a key role.
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