Restricciones operativas relacionadas con el ruido en el aeropuerto de Barcelona

In this essay we look to reflect on the problems of noise pollution emitted by aircrafts, in the vicinity of airports and how they seek to rectify this. A complex issue with many conflicting interests, on one hand the welfare of the people who live near the airports, and on the other hand, the necessary growth and expansion of airport infrastructure, to provide economic development to the city and surrounding areas. One of the measures to mitigate the noise impact is to apply operational restrictions on the loudest aircrafts. We will dedicate a study to this measure in collaboration with Barcelona airport, this is motivated by a resolution of the Agencia Estatal de Seguridad Aérea (AESA), published in the Boletin Oficial del Estado (BOE). This explains the operational restrictions to be introduced from the 1st of January of 2012 in Barcelona airport. To understand and interpret the resolution we will need to know some concepts such as: noise quantification; ICAO's classification for aircraft's noise certification, and the applicable laws that lead airports to take operational restrictions which set action plans to mitigate the noise impact. We must emphasize the fact that noise laws are becoming more restrictive due to the growing use of aircraft as a transportation medium. As demonstrated in our research, manufacturers and airline companies continue to use technological developments to create quieter fleets in anticipation of increasingly severe regulations.En este trabajo pretendemos reflejar la problemática en la que se ven inmersos los aeropuertos para combatir el ruido provocado por las aeronaves en las proximidades de éstos. Una problemática en la que chocan dos intereses. Por un lado, el bienestar de las personas que viven en las proximidades del aeropuerto y por otro lado la creciente y necesaria utilización de la infraestructura aeroportuaria para el desarrollo económico de las ciudades. Una de las medidas para mitigar el impacto acústico es la de restringir las operaciones de las aeronaves más ruidosas. Y a ésta medida le dedicaremos un estudio, en colaboración con el aeropuerto de Barcelona, el cual viene motivado por una resolución de la Agencia Estatal de Seguridad Aérea (AESA), publicada en el Boletín Oficial del Estado (BOE), en la cual se dice que se introducen restricciones operativas para las aeronaves marginalmente conformes (aeronaves más ruidosas) des del 1 de enero de 2012 en el aeropuerto de El Prat de Barcelona. Para llegar a entender esta resolución y saber interpretarla, necesitaremos pasar por explicar aquellos conceptos de acústica que nos permiten cuantificar el ruido de las aeronaves y la clasificación de estas según sus niveles de ruido certificados. Una vez explicado esto sólo nos faltara explicar la legislación aplicable que lleva a los aeropuertos a tomar medidas como esta en sus planes de acción elaborados para mitigar el impacto acústico. Cabe destacar que la legislación en cuanto a ruido en los aeropuertos se hace cada vez más restrictiva debido a que el uso del avión como medio de transporte aumenta año a año. Pero según hemos comprobado en nuestro estudio, los fabricantes y compañías aéreas utilizan muy bien las evoluciones tecnológicas para adelantarse a esta normativa cada vez más severa con flotas más silenciosas

Gaia Focused Product Release: A catalogue of sources around quasars to search for strongly lensed quasars

Context. Strongly lensed quasars are fundamental sources for cosmology. The Gaia space mission covers the entire sky with the unprecedented resolution of $0.18$" in the optical, making it an ideal instrument to search for gravitational lenses down to the limiting magnitude of 21. Nevertheless, the previous Gaia Data Releases are known to be incomplete for small angular separations such as those expected for most lenses. Aims. We present the Data Processing and Analysis Consortium GravLens pipeline, which was built to analyse all Gaia detections around quasars and to cluster them into sources, thus producing a catalogue of secondary sources around each quasar. We analysed the resulting catalogue to produce scores that indicate source configurations that are compatible with strongly lensed quasars. Methods. GravLens uses the DBSCAN unsupervised clustering algorithm to detect sources around quasars. The resulting catalogue of multiplets is then analysed with several methods to identify potential gravitational lenses. We developed and applied an outlier scoring method, a comparison between the average BP and RP spectra of the components, and we also used an extremely randomised tree algorithm. These methods produce scores to identify the most probable configurations and to establish a list of lens candidates. Results. We analysed the environment of 3 760 032 quasars. A total of 4 760 920 sources, including the quasars, were found within 6" of the quasar positions. This list is given in the Gaia archive. In 87\% of cases, the quasar remains a single source, and in 501 385 cases neighbouring sources were detected. We propose a list of 381 lensed candidates, of which we identified 49 as the most promising. Beyond these candidates, the associate tables in this Focused Product Release allow the entire community to explore the unique Gaia data for strong lensing studies further.Comment: 35 pages, 60 figures, accepted for publication by Astronomy and Astrophysic

Pulsations in main sequence OBAF-type stars

CONTEXT: The third Gaia data release provides photometric time series covering 34 months for about 10 million stars. For many of those stars, a characterisation in Fourier space and their variability classification are also provided. This paper focuses on intermediate- to high-mass (IHM) main sequence pulsators (M ≥  1.3 M⊙) of spectral types O, B, A, or F, known as β Cep, slowly pulsating B (SPB), δ Sct, and γ Dor stars. These stars are often multi-periodic and display low amplitudes, making them challenging targets to analyse with sparse time series. AIMS: We investigate the extent to which the sparse Gaia DR3 data can be used to detect OBAF-type pulsators and discriminate them from other types of variables. We aim to probe the empirical instability strips and compare them with theoretical predictions. The most populated variability class is that of the δ Sct variables. For these stars, we aim to confirm their empirical period-luminosity (PL) relation, and verify the relation between their oscillation amplitude and rotation. METHODS: All datasets used in this analysis are part of the Gaia DR3 data release. The photometric time series were used to perform a Fourier analysis, while the global astrophysical parameters necessary for the empirical instability strips were taken from the Gaia DR3 gspphot tables, and the v sin i data were taken from the Gaia DR3 esphs tables. The δ Sct PL relation was derived using the same photometric parallax method as the one recently used to establish the PL relation for classical Cepheids using Gaia data. RESULTS: We show that for nearby OBAF-type pulsators, the Gaia DR3 data are precise and accurate enough to pinpoint them in the Hertzsprung-Russell (HR) diagram. We find empirical instability strips covering broader regions than theoretically predicted. In particular, our study reveals the presence of fast rotating gravity-mode pulsators outside the strips, as well as the co-existence of rotationally modulated variables inside the strips as reported before in the literature. We derive an extensive period–luminosity relation for δ Sct stars and provide evidence that the relation features different regimes depending on the oscillation period. We demonstrate how stellar rotation attenuates the amplitude of the dominant oscillation mode of δ Sct stars. CONCLUSIONS: The Gaia DR3 time-series photometry already allows for the detection of the dominant (non-)radial oscillation mode in about 100 000 intermediate- and high-mass dwarfs across the entire sky. This detection capability will increase as the time series becomes longer, allowing the additional delivery of frequencies and amplitudes of secondary pulsation modes

Restricciones operativas relacionadas con el ruido en el aeropuerto de Barcelona

In this essay we look to reflect on the problems of noise pollution emitted by aircrafts, in the vicinity of airports and how they seek to rectify this. A complex issue with many conflicting interests, on one hand the welfare of the people who live near the airports, and on the other hand, the necessary growth and expansion of airport infrastructure, to provide economic development to the city and surrounding areas. One of the measures to mitigate the noise impact is to apply operational restrictions on the loudest aircrafts. We will dedicate a study to this measure in collaboration with Barcelona airport, this is motivated by a resolution of the Agencia Estatal de Seguridad Aérea (AESA), published in the Boletin Oficial del Estado (BOE). This explains the operational restrictions to be introduced from the 1st of January of 2012 in Barcelona airport. To understand and interpret the resolution we will need to know some concepts such as: noise quantification; ICAO's classification for aircraft's noise certification, and the applicable laws that lead airports to take operational restrictions which set action plans to mitigate the noise impact. We must emphasize the fact that noise laws are becoming more restrictive due to the growing use of aircraft as a transportation medium. As demonstrated in our research, manufacturers and airline companies continue to use technological developments to create quieter fleets in anticipation of increasingly severe regulations.En este trabajo pretendemos reflejar la problemática en la que se ven inmersos los aeropuertos para combatir el ruido provocado por las aeronaves en las proximidades de éstos. Una problemática en la que chocan dos intereses. Por un lado, el bienestar de las personas que viven en las proximidades del aeropuerto y por otro lado la creciente y necesaria utilización de la infraestructura aeroportuaria para el desarrollo económico de las ciudades. Una de las medidas para mitigar el impacto acústico es la de restringir las operaciones de las aeronaves más ruidosas. Y a ésta medida le dedicaremos un estudio, en colaboración con el aeropuerto de Barcelona, el cual viene motivado por una resolución de la Agencia Estatal de Seguridad Aérea (AESA), publicada en el Boletín Oficial del Estado (BOE), en la cual se dice que se introducen restricciones operativas para las aeronaves marginalmente conformes (aeronaves más ruidosas) des del 1 de enero de 2012 en el aeropuerto de El Prat de Barcelona. Para llegar a entender esta resolución y saber interpretarla, necesitaremos pasar por explicar aquellos conceptos de acústica que nos permiten cuantificar el ruido de las aeronaves y la clasificación de estas según sus niveles de ruido certificados. Una vez explicado esto sólo nos faltara explicar la legislación aplicable que lleva a los aeropuertos a tomar medidas como esta en sus planes de acción elaborados para mitigar el impacto acústico. Cabe destacar que la legislación en cuanto a ruido en los aeropuertos se hace cada vez más restrictiva debido a que el uso del avión como medio de transporte aumenta año a año. Pero según hemos comprobado en nuestro estudio, los fabricantes y compañías aéreas utilizan muy bien las evoluciones tecnológicas para adelantarse a esta normativa cada vez más severa con flotas más silenciosas

Restricciones operativas relacionadas con el ruido en el aeropuerto de Barcelona

In this essay we look to reflect on the problems of noise pollution emitted by aircrafts, in the vicinity of airports and how they seek to rectify this. A complex issue with many conflicting interests, on one hand the welfare of the people who live near the airports, and on the other hand, the necessary growth and expansion of airport infrastructure, to provide economic development to the city and surrounding areas. One of the measures to mitigate the noise impact is to apply operational restrictions on the loudest aircrafts. We will dedicate a study to this measure in collaboration with Barcelona airport, this is motivated by a resolution of the Agencia Estatal de Seguridad Aérea (AESA), published in the Boletin Oficial del Estado (BOE). This explains the operational restrictions to be introduced from the 1st of January of 2012 in Barcelona airport. To understand and interpret the resolution we will need to know some concepts such as: noise quantification; ICAO's classification for aircraft's noise certification, and the applicable laws that lead airports to take operational restrictions which set action plans to mitigate the noise impact. We must emphasize the fact that noise laws are becoming more restrictive due to the growing use of aircraft as a transportation medium. As demonstrated in our research, manufacturers and airline companies continue to use technological developments to create quieter fleets in anticipation of increasingly severe regulations.En este trabajo pretendemos reflejar la problemática en la que se ven inmersos los aeropuertos para combatir el ruido provocado por las aeronaves en las proximidades de éstos. Una problemática en la que chocan dos intereses. Por un lado, el bienestar de las personas que viven en las proximidades del aeropuerto y por otro lado la creciente y necesaria utilización de la infraestructura aeroportuaria para el desarrollo económico de las ciudades. Una de las medidas para mitigar el impacto acústico es la de restringir las operaciones de las aeronaves más ruidosas. Y a ésta medida le dedicaremos un estudio, en colaboración con el aeropuerto de Barcelona, el cual viene motivado por una resolución de la Agencia Estatal de Seguridad Aérea (AESA), publicada en el Boletín Oficial del Estado (BOE), en la cual se dice que se introducen restricciones operativas para las aeronaves marginalmente conformes (aeronaves más ruidosas) des del 1 de enero de 2012 en el aeropuerto de El Prat de Barcelona. Para llegar a entender esta resolución y saber interpretarla, necesitaremos pasar por explicar aquellos conceptos de acústica que nos permiten cuantificar el ruido de las aeronaves y la clasificación de estas según sus niveles de ruido certificados. Una vez explicado esto sólo nos faltara explicar la legislación aplicable que lleva a los aeropuertos a tomar medidas como esta en sus planes de acción elaborados para mitigar el impacto acústico. Cabe destacar que la legislación en cuanto a ruido en los aeropuertos se hace cada vez más restrictiva debido a que el uso del avión como medio de transporte aumenta año a año. Pero según hemos comprobado en nuestro estudio, los fabricantes y compañías aéreas utilizan muy bien las evoluciones tecnológicas para adelantarse a esta normativa cada vez más severa con flotas más silenciosas

Gaia Focused Product Release: Spatial distribution of two diffuse interstellar bands

Diffuse interstellar bands (DIBs) are absorption features seen in optical and infrared spectra of stars and extragalactic objects that are probably caused by large and complex molecules in the galactic interstellar medium (ISM). Here we investigate the Galactic distribution and properties of two DIBs identified in almost six million stellar spectra collected by the Gaia Radial Velocity Spectrometer. These measurements constitute a part of the Gaia Focused Product Release to be made public between the Gaia DR3 and DR4 data releases. In order to isolate the DIB signal from the stellar features in each individual spectrum, we identified a set of 160 000 spectra at high Galactic latitudes (|b| ≥ 65) covering a range of stellar parameters which we consider to be the DIB-free reference sample. Matching each target spectrum to its closest reference spectra in stellar parameter space allowed us to remove the stellar spectrum empirically, without reference to stellar models, leaving a set of six million ISM spectra. Using the star's parallax and sky coordinates, we then allocated each ISM spectrum to a voxel (VOlume piXEL) on a contiguous three-dimensional grid with an angular size of 1.8 (level 5 HEALPix) and 29 unequally sized distance bins. Identifying the two DIBs at 862.1 nm (λ862.1) and 864.8 nm (λ864.8) in the stacked spectra, we modelled their shapes and report the depth, central wavelength, width, and equivalent width (EW) for each, along with confidence bounds on these measurements. We then explored the properties and distributions of these quantities and compared them with similar measurements from other surveys. Our main results are as follows: (1) the strength and spatial distribution of the DIB λ862.1 are very consistent with what was found in Gaia DR3, but for this work we attained a higher signal-to-noise ratio in the stacked spectra to larger distances, which allowed us to trace DIBs in the outer spiral arm and beyond the Scutum-Centaurus spiral arm; (2) we produced an all-sky map below ±65 of Galactic latitude to ∼4000 pc of both DIB features and their correlations; (3) we detected the signals of DIB λ862.1 inside the Local Bubble (≲200 pc); and (4) there is a reasonable correlation with the dust reddening found from stellar absorption and EWs of both DIBs with a correlation coefficient of 0.90 for λ862.1 and 0.77 for λ864.8.</p

Discovery of a dormant 33 solar-mass black hole in pre-release Gaia astrometry

Abstract: Context. Gravitational waves from black-hole (BH) merging events have revealed a population of extra-galactic BHs residing in short-period binaries with masses that are higher than expected based on most stellar evolution models - and also higher than known stellar-origin black holes in our Galaxy. It has been proposed that those high-mass BHs are the remnants of massive metal-poor stars. Aims. Gaia astrometry is expected to uncover many Galactic wide-binary systems containing dormant BHs, which may not have been detected before. The study of this population will provide new information on the BH-mass distribution in binaries and shed light on their formation mechanisms and progenitors. Methods. As part of the validation efforts in preparation for the fourth Gaia data release (DR4), we analysed the preliminary astrometric binary solutions, obtained by the Gaia Non-Single Star pipeline, to verify their significance and to minimise false-detection rates in high-mass-function orbital solutions. Results. The astrometric binary solution of one source, Gaia BH3, implies the presence of a 32 :70 +/- 0 :82 M-circle dot BH in a binary system with a period of 11.6 yr. Gaia radial velocities independently validate the astrometric orbit. Broad-band photometric and spectroscopic data show that the visible component is an old, very metal-poor giant of the Galactic halo, at a distance of 590 pc. Conclusions. The BH in the Gaia BH3 system is more massive than any other Galactic stellar-origin BH known thus far. The low metallicity of the star companion supports the scenario that metal-poor massive stars are progenitors of the high-mass BHs detected by gravitational-wave telescopes. The Galactic orbit of the system and its metallicity indicate that it might belong to the Sequoia halo substructure. Alternatively, and more plausibly, it could belong to the ED-2 stream, which likely originated from a globular cluster that had been disrupted by the Milky Way