20 research outputs found
The dire consequences of multiple failed hypospadias repairs: a case report of a cavernosal reconstruction with mesh and malleable prosthesis
No full text20.500.12530/87857The management of hypospadias during the neonatal period should be carried out exclusively in specialized medical centers because of the potential dire complications that may arise. In this report, we present a case of a 22-year-old male who underwent thirteen unsuccessful surgical procedures for his penoscrotal hypospadias in various hospitals. The purpose of this case report is to describe the surgical correction of severe corporal fibrosis and penile curvature that ensued from the multiple failed hypospadias corrections. We implanted an extra cavernosal malleable penile prosthesis and reconstructed the tunica albuginea defect with surgical meshes used in hernia repairs
Very short baseline interferometry: assessment of the relative stability of the GPS stations at the Yebes Observatory (Spain)
No full textAstrometric Apparent Motion of High-redshift Radio Sources
No full textRadio-loud quasars at high redshift (z ≥ 4) are rare objects in the universe and rarely observed with Very Long Baseline Interferometry (VLBI). But some of them have flux density sufficiently high for monitoring of their apparent position. The instability of the astrometric positions could be linked to the astrophysical process in the jetted active galactic nuclei in the early universe. Regular observations of the high-redshift quasars are used for estimating their apparent proper motion over several years. We have undertaken regular VLBI observations of several high-redshift quasars at 2.3 GHz (S band) and 8.4 GHz (X band) with a network of five radio telescopes: 40 m Yebes (Spain), 25 m Sheshan (China), and three 32 m telescopes of the Quasar VLBI Network (Russia)—Svetloe, Zelenchukskaya, and Badary. Additional facilities joined this network occasionally. The sources have also been observed in three sessions with the European VLBI Network in 2018-2019 and one Long Baseline Array experiment in 2018. In addition, several experiments conducted with the Very Long Baseline Array in 2017-2018 were used to improve the time sampling and the statistics. Based on these 37 astrometric VLBI experiments between 2017 and 2021, we estimated the apparent proper motions of four quasars: 0901+697, 1428+422, 1508+572, and 2101+600.Astrodynamics & Space Mission
Principios de la inacción: un estudio del aburrimiento desde la perspectiva de Ortega
No full textThe orteguian proposal has found many detractors who had questioned its philosophical character
because of its lack of sistematicity. However, this present article pretends to call into question that
criticism from a conceptual study, which conclusion has to be justified upon Ortega y Gasset’s
philosophical principles. Thus, this study is going to focus on his remarks on boredom, present in
his prologue to the book Veinte años de caza mayor, of Conde de Yebes. In order to make explicit the
relation between this concept and the rest of his work, the other claim of this article is to show how
other notions treated by the author, such as decision, action, circunstance or absorption reaffirm,
dragged to their last conclusions, the results which Ortega exposes with regard to boredom.La propuesta orteguiana ha hallado múltiples detractores que han cuestionado su carácter filosófico
por su falta de sistematicidad. Sin embargo, el presente artículo pretende poner en duda esta crítica
a partir de un estudio conceptual, cuyo término se encuentre justificado por los principios de
la filosofía de Ortega y Gasset. Por ello, este estudio va a centrarse en sus comentarios sobre el
aburrimiento, que dedica en su prólogo a la obra Veinte años de caza mayor del Conde de Yebes. De
cara a explicitar la relación entre este concepto y el resto de su obra, otra pretensión del artículo es
mostrar cómo otras nociones tratadas por el autor, tales como la decisión, la acción, la circunstancia
o el ensimismamiento, reafirman, llevadas a sus conclusiones últimas, los resultados que expone
Ortega con respecto al aburrimiento
Deep survey of millimeter RRLs towards the planetary nebulae IC 418 and NGC 7027
No full text16 pages, 11 figures, 3 tablesThe circumstellar environments of PNe are wonderful chemically rich
astrophysical laboratories in which the ionization of atoms and the formation
of simple and complex molecules can be studied. The new high-sensitivity
receivers open the possibility to carry out deep observations, essential to
unveil weak atomic and molecular spectra in the mm range. The main goal of this
work is to study the emission lines detected in the spectra of the bright
C-rich PNe IC 418 and NGC 7027 and to identify all those emission features
associated with radio recombination lines (RRLs) of light elements. We aim to
analyze the RRLs detected on each source, and to model the sources and derive
their physical parameters. This work allows us to provide the most complete and
updated catalog of RRLs in space, carried out at 2, 3 and 7 mm with the IRAM
30m and the Yebes 40m radio telescopes. We compare these observational data
sets with synthetic models produced with the radiation transfer code Co3RaL.
Our observations reveal the presence of several H and He I RRLs at mm
wavelengths in the spectra of IC 418 and NGC 7027 and also of HeIIi RRLs in the
spectrum of NGC 7027. Many of these lines had remained undetected until now due
to their weakness and the lack of high-sensitivity observations at these
frequencies. The data also confirm the absence of molecular emission towards IC
418, above a detection level of ~3 mK [Tmb]. These mm observations represent
the most extended RRL line survey of two C-rich PNe carried out so far, with
most of the lines never reported before. These extremely complete catalogs
evidence the importance of high-sensitivity observations and are expected to be
very helpful in the line identification process in mm observations, in
particular for still unknown or poorly characterized molecular species existing
in the vicinity of ionized environments.THR, DAGH, AMT, and RB acknowledge the support from the State Research Agency (AEI) of the Ministry of Science, Innovation and Universities (MICIU) of the Government of Spain, and the European Regional Development Fund (ERDF), under grants PID2020-115758GB-I00/AEI/10.13039/
501100011033 and PID2023-147325NB-I00/AEI/10.13039/501100011033. THR acknowledges support from grant PID2020-115758GB-I00/PRE2021-100042 financed by MCIN/AEI/10.13039/501100011033 and the European Social Fund Plus (ESF+). JA, JPF, JJDL, and VB are partially supported by I+D+i projects
PID2019-105203GB-C21 and PID2023-146056NB-C21, funded by the Spanish MCIN/AEI/10.13039/501100011033 and EU/ERDF. JPF also acknowledges
support from grants PID2023-147545NB-I00 and PID2023-146056NB-C22. MAGM acknowledge to be funded by the European Union (ERC, CET-3PO, 101042610). Views and opinions expressed are however those of the author(s) only and do not necessarily reflect those of the European Union or the European Research Council Executive Agency. Neither the European Union nor the granting authority can be held responsible for them. This work is based on observations carried out under project number 158-21 with the IRAM 30m telescope.
IRAM is supported by INSU/CNRS (France), MPG (Germany) and IGN (Spain).
Based on observations carried out with the Yebes 40 m telescope (22A011).
The 40 m radio telescope at Yebes Observatory is operated by the Spanish
Geographic Institute (IGN; Ministerio de Transportes y Movilidad Sostenible).
This publication is based upon work from COST Action CA21126 – Carbon
molecular nanostructures in space (NanoSpace), supported by COST (European
Cooperation in Science and Technology)Peer reviewe
The impact of new estimates of models of stellar motion from VLBI on the alignment of the optically bright Gaia frame to ICRF3
No full textFunding Information: The authors acknowledge use of the Very Long Baseline Array under the US Naval Observatory's time allocation. This work supports USNO's ongoing research into the celestial reference frame and geodesy. We thank also the Socorro correlator for reliably and quickly providing the correlated data. The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc. This project is supported by the DFG grants No. SCHU 1103/7-2, No. HE 5937/2-2, and SCHU 1103/26-1. M. H. Xu was supported by the Academy of Finland project No. 315721. This work has made use of the data from the European Space Agency mission Gaia processed by the Gaia Data Processing and Analysis Consortium. Funding for the DPAC has been provided by national institutions, in particular the institutions participating in the Gaia Multilateral Agreement. Funding Information: The authors acknowledge use of the Very Long Baseline Array under the US Naval Observatory’s time allocation. This work supports USNO’s ongoing research into the celestial reference frame and geodesy. We thank also the Socorro correlator for reliably and quickly providing the correlated data. The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc. This project is supported by the DFG grants No. SCHU 1103/7-2, No. HE 5937/2-2, and SCHU 1103/26-1. M. H. Xu was supported by the Academy of Finland project No. 315721. This work has made use of the data from the European Space Agency mission Gaia processed by the Gaia Data Processing and Analysis Consortium. Funding for the DPAC has been provided by national institutions, in particular the institutions participating in the Gaia Multilateral Agreement. Publisher Copyright: © Copyright owned by the author(s) under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License (CC BY-NC-ND 4.0).The reference frame determined by Gaia EDR3, Gaia-CRF3, is aligned to the International Celestial Reference System by referring to counterparts in its latest realization, the third International Celestial Reference Frame (ICRF3), which is calculated from very long baseline interferometry (VLBI) observations of extragalactic objects at radio frequencies. The objects in ICRF3, although bright at radio frequencies, are mostly faint at optical frequencies. The non-rotation of the optically bright Gaia frame to ICRF3 has to be tested separately because the Gaia dataset is known to be magnitude-dependent in terms of astrometric calibration. This can be done by identifying additional counterparts besides objects in ICRF3. Suitable counterparts are radio stars observed by VLBI relative to extragalactic objects in ICRF3 using phase-referencing. We discuss the rotational differences, i.e., orientation and spin, between the optically bright Gaia EDR3 and models of stellar motion from VLBI. In particular, we show the effects of improved models of stellar motion, for which we extended the time series from literature or archives with new VLBI results.Peer reviewe
H2O MegaMaser emission in NGC 4258 indicative of a periodic disc instability
No full textH2O MegaMaser emission may arise from thin gas discs surrounding the massive nuclei of galaxies such as NGC 4258, but the physical conditions responsible for the amplified emission are unclear. A detailed view of these regions is possible using the very high angular resolution afforded by space very long baseline interferometry (SVLBI). Here we report SVLBI experiments conducted using the orbiting RadioAstron Observatory that have resulted in detections of the H2O 22 GHz emission in NGC 4258, with Earth–space baselines of 1.3, 9.5 and 19.5 Earth diameters. Observations at the highest angular resolutions of 11 and 23 μas show distinct and regularly spaced regions within the rotating disc, at an orbital radius of about 0.126 pc. These observations at three subsequent epochs also indicate a time evolution of the emission features, with a sudden rise in amplitude followed by a slow decay. The formation of these emission regions, their regular spacing and their time-dependent behaviour appear consistent with the occurrence of a periodic magneto-rotational instability in the disc. This type of shear-driven instability within the differentially rotating disc has been suggested to be the mechanism governing the radial momentum transfer and viscosity within a mass-accreting disc. The connection of the H2O MegaMaser activity with the magneto-rotational instability activity would make it an indicator of the mass-accretion rate in the nuclear disc of the host galaxy. © 2022, The Author(s), under exclusive licence to Springer Nature Limited.Lavochkin Scientific and Production AssociationState Space CorporationNational Science Foundation, NSFNational Natural Science Foundation of China, NSFC, (11433008)Chinese Academy of Sciences, CAS, (2019VMA0040, 2021VMA0008, 2022VMA0019)Ministry of Education and Science of the Russian Federation, Minobrnauka, (FEUZ-2020-0030)Youth Innovation Promotion Association of the Chinese Academy of Sciences, YIPA CASLebedev Physical Institute, Russian Academy of Sciences, LPI RASÖsterreichische Kardiologische Gesellschaft, ASCFunding text 1: We dedicate this paper to the memory of our colleague and friend Nikolai Kardashev, a man of great vision, who persevered to realize the RadioAstron mission. We thank the observatory staff of the ground telescope stations Effelsberg, Green Bank, Torun, Yebes and the Kwazar stations Kalyazin, Svetloe and Badary for their participation in the observations. These observations have been correlated at the ASC DiFX correlator and we thank the Correlator Team members for their contributions, their repeated re-correlation efforts and their unfailing support of this project. We also thank the other members of the H2 O MegaMaser Team for their support for this project: A. Alakoz, S. Ellingsen, I. Litovchenko, J. Moran and A. Tolmachev. We thank E. Vorobyov (University of Vienna) for valuable discussions about the stability criteria for the disc. The RadioAstron project has been led by the AstroSpace Centre of the Lebedev Physical Institute of the Russian Academy of Sciences and the Lavochkin Scientific and Production Association under a contract with the State Space Corporation ROSCOSMOS, in collaboration with partner organizations in Russia and other countries. The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under a cooperative agreement by Associated Universities, Inc. The European VLBI Network is a joint facility of independent European, African, Asian and North American radio astronomy institutes. W.A.B. acknowledges the support from the National Natural Science Foundation of China under grant no. 11433008 and the Chinese Academy of Sciences President’s International Fellowship Initiative under grant nos. 2019VMA0040, 2021VMA0008 and 2022VMA0019. T.A. acknowledges the grant support from the Youth Innovation Promotion Association of CAS. AMS was supported by the Ministry of Education and Science of Russia (the basic part of the State assignment, K 1567 no. FEUZ-2020-0030).Funding text 2: We dedicate this paper to the memory of our colleague and friend Nikolai Kardashev, a man of great vision, who persevered to realize the RadioAstron mission. We thank the observatory staff of the ground telescope stations Effelsberg, Green Bank, Torun, Yebes and the Kwazar stations Kalyazin, Svetloe and Badary for their participation in the observations. These observations have been correlated at the ASC DiFX correlator and we thank the Correlator Team members for their contributions, their repeated re-correlation efforts and their unfailing support of this project. We also thank the other members of the HO MegaMaser Team for their support for this project: A. Alakoz, S. Ellingsen, I. Litovchenko, J. Moran and A. Tolmachev. We thank E. Vorobyov (University of Vienna) for valuable discussions about the stability criteria for the disc. The RadioAstron project has been led by the AstroSpace Centre of the Lebedev Physical Institute of the Russian Academy of Sciences and the Lavochkin Scientific and Production Association under a contract with the State Space Corporation ROSCOSMOS, in collaboration with partner organizations in Russia and other countries. The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under a cooperative agreement by Associated Universities, Inc. The European VLBI Network is a joint facility of independent European, African, Asian and North American radio astronomy institutes. W.A.B. acknowledges the support from the National Natural Science Foundation of China under grant no. 11433008 and the Chinese Academy of Sciences President’s International Fellowship Initiative under grant nos. 2019VMA0040, 2021VMA0008 and 2022VMA0019. T.A. acknowledges the grant support from the Youth Innovation Promotion Association of CAS. AMS was supported by the Ministry of Education and Science of Russia (the basic part of the State assignment, K 1567 no. FEUZ-2020-0030).
A persistent double nuclear structure in 3C 84
No full text3C 84 (NGC 1275) is the radio source at the centre of the Perseus cluster and exhibits a bright radio jet. We observed the source with the Global Millimeter VLBI Array (GMVA) between 2008 and 2015, with a typical angular resolution of ∼50 μas. The observations revealed a consistent double nuclear structure separated by ∼770 gravitational radii assuming a black hole mass of 3.2 × 108 M⊙. The region is likely too broad and bright to be the true jet base anchored in the accretion disc or black hole ergosphere. A cone and parabola were fit to the stacked (time averaged) image of the nuclear region. The data did not strongly prefer either fit, but combined with a jet/counter-jet ratio analysis, an upper limit on the viewing angle to the inner jet region of ≤35° was found. This provides evidence for a variation of the viewing angle along the jet (and therefore a bent jet) within ∼0.5 pc of the jet launching region. In the case of a conical jet, the apex is located ∼2400 gravitational radii upstream of the bright nuclear region and up to ∼600 gravitational radii upstream in the parabolic case. We found a possible correlation between the brightness temperature and relative position angle of the double nuclear components, which may indicate rotation within the jet. © 2021 The Author(s).This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (NRF-2021R1A6A3A01086420). JAH was supported by Korea Research Fellowship Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science and ICT, South Korea (2018H1D3A1A02032824) and the research grant (2021R1C1C1009973). S-SL was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MIST) (2020R1A2C2009003). J-YK is supported for this research by the International Max-Planck Research School (IMPRS) for Astronomy and Astrophysics at the University of Bonn and Cologne. This research was supported by an appointment to the NASA Postdoctoral Program at the Goddard Space Flight Center, administered by Universities Space Research Association through a contract with NASA. RL acknowledges the support of the Spanish Ministerio de Economía y Competitividad (grant PID2019-108995GB-C21), the Consejería de Economía, Conocimiento, Empresas y Universidad, Junta de Andalucía (grant P18-FR-1769), and the Consejo Superior de Investigaciones Científicas (grant 2019AEP112). GFP is supported for this research by the International Max-Planck Research School (IMPRS) for Astronomy and Astrophysics at the University of Bonn and Cologne. ST and MK acknowledge support via NRF grant 2019R1F1A1059721. This research has made use of data obtained with the Global Millimeter VLBI Array (GMVA), which consists of telescopes operated by the MPIfR, IRAM, Onsala, Metsahovi, Yebes, the Korean VLBI Network, the Green Bank Observatory, and the Very Long Baseline Array (VLBA). The VLBA is an instrument of the NRAO, which is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc. The data were correlated at the correlator of the Max Planck Institute for Radioastronomy (MPIfR) in Bonn, Germany. This work made use of the Swinburne University of Technology software correlator, developed as part of the Australian Major National Research Facilities Programme and operated under licence.With funding from the Spanish government through the Severo Ochoa Centre of Excellence accreditation SEV-2017-0709.Peer reviewe
A ring-like accretion structure in M87 connecting its black hole and jet
No full textLu, Ru-Sen et al.--Full list of authors: Lu, Ru-Sen; Asada, Keiichi; Krichbaum, Thomas P.; Park, Jongho; Tazaki, Fumie; Pu, Hung-Yi; Nakamura, Masanori; Lobanov, Andrei; Hada, Kazuhiro; Akiyama, Kazunori; Kim, Jae-Young; Marti-Vidal, Ivan; Gomez, Jose L.; Kawashima, Tomohisa; Yuan, Feng; Ros, Eduardo; Alef, Walter; Britzen, Silke; Bremer, Michael; Broderick, Avery E.; Doi, Akihiro; Giovannini, Gabriele; Giroletti, Marcello; Ho, Paul T. P.; Honma, Mareki; Hughes, David H.; Inoue, Makoto; Jiang, Wu; Kino, Motoki; Koyama, Shoko; Lindqvist, Michael; Liu, Jun; Marscher, Alan P.; Matsushita, Satoki; Nagai, Hiroshi; Rottmann, Helge; Savolainen, Tuomas; Schuster, Karl-Friedrich; Shen, Zhi-Qiang; de Vicente, Pablo; Walker, R. Craig; Yang, Hai; Zensus, J. Anton; Algaba, Juan Carlos; Allardi, Alexander; Bach, Uwe; Berthold, Ryan; Bintley, Dan; Byun, Do-Young; Casadio, Carolina; Chang, Shu-Hao; Chang, Chih-Cheng; Chang, Song-Chu; Chen, Chung-Chen; Chen, Ming-Tang; Chilson, Ryan; Chuter, Tim C.; Conway, John; Crew, Geoffrey B.; Dempsey, Jessica T.; Dornbusch, Sven; Faber, Aaron; Friberg, Per; Garcia, Javier Gonzalez; Garrido, Miguel Gomez; Han, Chih-Chiang; Han, Kuo-Chang; Hasegawa, Yutaka; Herrero-Illana, Ruben; Huang, Yau-De; Huang, Chih-Wei L.; Impellizzeri, Violette; Jiang, Homin; Jinchi, Hao; Jung, Taehyun; Kallunki, Juha; Kirves, Petri; Kimura, Kimihiro; Koay, Jun Yi; Koch, Patrick M.; Kramer, Carsten; Kraus, Alex; Kubo, Derek; Kuo, Cheng-Yu; Li, Chao-Te; Lin, Lupin Chun-Che; Liu, Ching-Tang; Liu, Kuan-Yu; Lo, Wen-Ping; Lu, Li-Ming; MacDonald, Nicholas; Martin-Cocher, Pierre; Messias, Hugo; Meyer-Zhao, Zheng; Minter, Anthony; Nair, Dhanya G.; Nishioka, Hiroaki; Norton, Timothy J.; Nystrom, George; Ogawa, Hideo; Oshiro, Peter; Patel, Nimesh A.; Pen, Ue-Li; Pidopryhora, Yurii; Pradel, Nicolas; Raffin, Philippe A.; Rao, Ramprasad; Ruiz, Ignacio; Sanchez, Salvador; Shaw, Paul; Snow, William; Sridharan, T. K.; Srinivasan, Ranjani; Tercero, Belen; Torne, Pablo; Traianou, Efthalia; Wagner, Jan; Walther, Craig; Wei, Ta-Shun; Yang, Jun; Yu, Chen-YuThe nearby radio galaxy M87 is a prime target for studying black hole accretion and jet formation1,2. Event Horizon Telescope observations of M87 in 2017, at a wavelength of 1.3 mm, revealed a ring-like structure, which was interpreted as gravitationally lensed emission around a central black hole3. Here we report images of M87 obtained in 2018, at a wavelength of 3.5 mm, showing that the compact radio core is spatially resolved. High-resolution imaging shows a ring-like structure of 8.4+0.5−1.1 Schwarzschild radii in diameter, approximately 50% larger than that seen at 1.3 mm. The outer edge at 3.5 mm is also larger than that at 1.3 mm. This larger and thicker ring indicates a substantial contribution from the accretion flow with absorption effects, in addition to the gravitationally lensed ring-like emission. The images show that the edge-brightened jet connects to the accretion flow of the black hole. Close to the black hole, the emission profile of the jet-launching region is wider than the expected profile of a black-hole-driven jet, suggesting the possible presence of a wind associated with the accretion flow. © The Author(s) 2023.R.-S.L. is supported by the Key Program of the National Natural Science Foundation of China (grant no. 11933007); the Key Research Program of Frontier Sciences, CAS (grant no. ZDBS-LY-SLH011); the Shanghai Pilot Program for Basic Research, Chinese Academy of Sciences, Shanghai Branch (JCYJ-SHFY-2022-013) and the Max Planck Partner Group of the MPG and the CAS. R.-S.L. thanks L. Blackburn, L. Chen, Y.-Z. Cui, L. Huang, R. S. de Souza and Y. Mizuno for discussions on data calibration and interpretation. J.P. acknowledges financial support through the EACOA Fellowship awarded by the East Asia Core Observatories Association, which consists of the Academia Sinica Institute of Astronomy and Astrophysics, the National Astronomical Observatory of Japan, Center for Astronomical Mega-Science, Chinese Academy of Sciences and the Korea Astronomy and Space Science Institute. H.-Y.P. acknowledges the support of the Ministry of Education Yushan Young Scholar Program, the Ministry of Science and Technology under grant no. 110-2112-M-003-007-MY2 and the Physics Division, National Center for Theoretical Sciences. K.H. is supported by JSPS KAKENHI grant nos. JP18H03721, JP19H01943, JP18KK0090, JP2101137, JP2104488 and JP22H00157. J.-Y. Kim acknowledges support from the National Research Foundation (NRF) of Korea (grant no. 022R1C1C1005255). I.M.-V. acknowledges support from research project PID2019-108995GB-C22 of Ministerio de Ciencia e Innovacion (Spain), from the GenT Project CIDEGENT/2018/021 of Generalitat Valenciana (Spain), and from the Project European Union NextGenerationEU (PRTR-C17I1). F.Y. and H.Y. are supported by the Natural Science Foundation of China (grant nos. 12133008, 12192220 and 12192223) and China Manned Space Project (CMS-CSST-2021-B02). A.E.B. thanks the Delaney Family for their financial support through the Delaney Family John A. Wheeler Chair at Perimeter Institute. This work was supported in part by Perimeter Institute for Theoretical Physics. Research at Perimeter Institute is supported by the Government of Canada through the Department of Innovation, Science and Economic Development Canada and by the Province of Ontario through the Ministry of Economic Development, Job Creation and Trade. A.E.B. received further financial support from the Natural Sciences and Engineering Research Council of Canada through a Discovery Grant. S.K. acknowledges the Female Researchers Flowering Plan from MEXT of Japan, which supports research activities of female researchers. The research at Boston University was supported in part by NASA Fermi Guest Investigator grant no. 80NSSC20K1567. H. Nagai is supported by JSPS KAKENHI grant nos. JP18K03709 and JP21H01137. T.S. was partly supported by the Academy of Finland projects 274477, 284495, 312496 and 315721. P.d.V. and B.T. thank the support from the European Research Council through Synergy Grant ERC-2013-SyG, G.A. 610256 (NANOCOSMOS), and from the Spanish Ministerio de Ciencia e Innovación (MICIU) through project PID2019-107115GB-C21. B.T. also thanks the Spanish MICIU for funding support from grant nos. PID2019-106235GB-I00 and PID2019-105203GB-C21. This publication acknowledges project M2FINDERS, which is funded by the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement no. 101018682). C.C. acknowledges support by the ERC under the Horizon ERC Grants 2021 programme under grant agreement no. 101040021. D.G.N. acknowledges funding from Conicyt through Fondecyt Postdoctorado (project code 3220195). This research has made use of data obtained using the Global Millimetre VLBI Array (GMVA), which consists of telescopes operated by the Max-Planck-Institut für Radioastronomie (MPIfR), IRAM, Onsala, Metsähovi Radio Observatory, Yebes, the Korean VLBI Network, the Greenland Telescope, the Green Bank Observatory (GBT) and the Very Long Baseline Array (VLBA). The VLBA and the GBT are facilities of the National Science Foundation (NSF) operated under cooperative agreement by Associated Universities. The data were correlated at the VLBI correlator of MPIfR in Bonn, Germany. This paper makes use of the following ALMA data: ADS/JAO.ALMA\#2017.1.00842.V. ALMA is a partnership of ESO (representing its member states), NSF (USA) and NINS (Japan), together with NRC (Canada), MOST and ASIAA (Taiwan) and KASI (Republic of Korea), in cooperation with the Republic of Chile. The Joint ALMA Observatory is operated by ESO, AUI/NRAO and NAOJ. The Greenland Telescope (GLT) is operated by the Academia Sinica Institute of Astronomy and Astrophysics (ASIAA) and the Smithsonian Astrophysical Observatory (SAO). The GLT is part of the ALMA–Taiwan project and is supported in part by the Academia Sinica (AS) and the Ministry of Science and Technology of Taiwan; 103-2119-M-001-010-MY2, 105-2112-M-001-025-MY3, 105-2119-M-001-042, 106-2112-M-001-011, 106-2119-M-001-013, 106-2119-M-001-027, 106-2923-M-001-005, 107-2119-M-001-017, 107-2119-M-001-020, 107-2119-M-001-041, 107-2119-M-110-005, 107-2923-M-001-009, 108-2112-M-001-048, 108-2112-M-001-051, 108-2923-M-001-002, 109-2112-M-001-025, 109-2124-M-001-005, 109-2923-M-001-001, 110-2112-M-003-007-MY2, 110-2112-M-001-033, 110-2124-M-001-007, 110-2923-M-001-001, and 110-2811-M-006-012. This research is based in part on observations obtained with the 100-m telescope of the MPIfR at Effelsberg, observations carried out at the IRM 30-m telescope operated by IRAM, which is supported by INSU/CNRS (France), MPG (Germany) and IGN (Spain), observations obtained with the Yebes 40-m radio telescope at the Yebes Observatory, which is operated by the Spanish Geographic Institute (IGN, Ministerio de Transportes, Movilidad y Agenda Urbana), and observations supported by the Green Bank Observatory, which is a main facility funded by the NSF operated by the Associated Universities. We acknowledge support from the Onsala Space Observatory national infrastructure for providing facilities and observational support. The Onsala Space Observatory receives funding from the Swedish Research Council through grant no. 2017-00648. This publication makes use of data obtained at the Metsähovi Radio Observatory, operated by Aalto University. It also makes use of VLBA data from the VLBA-BU Blazar Monitoring Program (BEAM-ME and VLBA-BU-BLAZAR; http://www.bu.edu/blazars/BEAM-ME.html), funded by NASA through the Fermi Guest Investigator Program.Peer reviewe
Is land subsidence increasing the exposure to sea level rise in Alexandria, Egypt?
No full textInternational audienceDelta margins are subject to relatively high rates of land subsidence and have the potential to significantly exacerbate future changes in sea levels predicted by global warming models used in impact studies. Through a combined analysis of GPS and persistent scatterer interferometry data, we determine that most of the coastline of Alexandria has been subject to moderate land subsidence over the past decade (0.4 mm/year on average and up to 2 mm/year locally). This contrasts to previous studies that suggested subsidence in excess of 3 mm/year. Based on our findings, we infer that on multi-century to millennia timescales, land subsidence in the area of Alexandria is dominated by tectonic setting and earthquakes or gravitational collapse episodes of a growth fault, whereas on shorter inter-seismic decadal to century timescales, subsidence rates are likely steady and moderate, in agreement with natural compaction and dewatering of the observed Holocene sediment layer
