Yebes 40 m radio telescope and the broad band Nanocosmos receivers at 7 mm and 3 mm for line surveys

Abstract

Context. Yebes 40 m radio telescope is the main and largest observing instrument at Yebes Observatory and is devoted to very long baseline interferometry (VLBI) and single-dish observations since 2010. It has been covering frequency bands between 2 GHz and 90 GHz in discontinuous and narrow windows in most cases in order to match the current needs of the European VLBI Network (EVN) and the Global Millimeter VLBI Array (GMVA). Aims. The Nanocosmos project, a European Union-funded synergy grant, has enabled an increase in the instantaneous frequency coverage of the Yebes 40 m radio telescope, making it possible to observe many molecular transitions with single tunings in singledish mode. This reduces the observing time and maximises the output from the telescope. Methods. We present technical specifications of the recently installed 31.5 − 50 GHz (Q band) and 72 − 90.5 GHz (W band) receivers along with the main characteristics of the telescope at these frequency ranges. We observed IRC+10216, CRL 2688, and CRL 618, which harbour a rich molecular chemistry, to demonstrate the capabilities of the new instrumentation for spectral observations in single-dish mode. Results. Our results show the high sensitivity of the telescope in the Q band. The spectrum of IRC+10126 offers an unprecedented signal-to-noise ratio for this source in this band. On the other hand, the spectrum normalised by the continuum flux towards CRL 618 in the W band demonstrates that the 40 m radio telescope produces comparable results to those from the IRAM 30 m radio telescope, although with a lower sensitivity. The new receivers fulfil one of the main goals of Nanocosmos and open up the possibility to study the spectrum of different astrophysical media with unprecedented sensitivity.

Discovery in space of ethanolamine, the simplest phospholipid head group

“…The observations were carried out with the Yebes 40-m telescope located in Yebes (Guadalajara, Spain), during six observing sessions in February 2020, as part of the project 20A008 (Principal Investigator I.J.-S.). We used the new Nanocosmos Q-band (7-mm) high-electron-mobility transistor receiver that enables ultrabroad-band observations in two linear polarizations ( 54 ). The receiver is connected to 16 fast Fourier transform spectrometers with a spectral coverage of 2.5 GHz and a spectral resolution of 38 kHz.…”

“…). We used the new Nanocosmos Q-band (7-mm) high-electronmobility transistor receiver that enables ultrabroad-band observations in two linear polarizations (54). The receiver is connected to 16 fast Fourier transform spectrometers with a spectral coverage of 2.5 GHz and a spectral resolution of 38 kHz.…”

New deuterated species in TMC-1: Detection of CH2DC4H with the QUIJOTE line survey

“…The T MB can be easily obtained by dividing the observed T A by the beam efficiency. Values of η MB have been provided by Tercero et al (2021). Furthermore, T * A was calibrated using two absorbers at different temperatures and the atmospheric transmission model (ATM; Cernicharo 1985;Pardo et al 2001).…”

Discovery of HCCCO and C5O in TMC-1 with the QUIJOTE line survey

“…New receivers, built within the Nanocosmos project 2 and installed at the Yebes 40 m radiotelescope, were used for the observations of TMC-1 (α J2000 = 4 h 41 m 41.9 s and δ J2000 = +25 • 41 27.0 ). A detailed description of the system is given by Tercero et al (2021). The receiver consists of two cold high electron mobility transistor amplifiers covering the 31.0−50.3 GHz band with horizontal and vertical polarisations.…”