Climbing walls to feel at home: Palestinian climbers re-appropriating space

Rock climbing is an outdoor activity that has recently become popular in Palestine partly due to the development of the Wadi Climbing project. A climbing community of local climbers has therefore developed and this implies new relationships and belonging ties between space and Palestinians are appearing. This article explores the ability of climbers to re-appropriate a space such as the natural landscape of the West Bank that has been under Israeli occupation since 1967La escalada es una actividad que se realiza al aire libre y que se ha popularizado recientemente en Palestina gracias, en parte, a la puesta en marcha del proyecto Wadi Climbing. Ello ha dado lugar a la aparición de una comunidad local de escaladores/as, lo que supone el desarrollo de nuevas relaciones y lazos de pertenencia entre la población palestina y el entorno. Este artículo explora la capacidad de dichos escaladores/as palestinos/as para reapropiarse de un espacio como el paisaje natural de Cisjordania, que vive bajo la ocupación israelí desde 196

Violent frontier architecture and artistic re-appropriation of borders: the production of space in Palestine and Western Sahara

Tesis doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Filosofía y Letras, Departamento de Estudios Árabes e Islámicos y Estudios Orientales. Fecha de lectura: 27-11-2019This PhD Thesis examines how frontier architecture functions, how it relates to artistic practices and what are the possibilities of an ethics of architecture. As argued by some authors, such as Bernard Tschumi, architectural structures are intrinsically performative and violent. Architecture becomes a violent event as soon as it intervenes in and obstructs life by preventing certain movements, by impossing certain choreographies or by avoiding access to certain spaces, for example. Architecture, then, performatively conditions and restricts the world. The border is the chosen landscape that I focus on, in order to theorize about the performativity and violence inherent to architecture. Two specific frontier contexts will be discussed to analyze how space is produced: the West Bank in Palestine, and Western Sahara. These borderlands are also addressed in relation to other borderscapes: the two fences of Ceuta and Melilla, the US-Mexico wall and the fences that are being built in Europe in order to manage the refugee crisis. The aim of looking at these different border structures is analyzing the similarities between them and discussing to what extent all these walls function similarly and are part of the same type of strategies for sociopolitical management. On the other hand, looking at the interaction between borders and bodies will allow to focus on techniques of resistance and re-appropriation that happen in these frontier contexts. Therefore, this PhD Thesis also explores the potential of artistic practices to intervene in border spaces both in Palestine and Western Sahara. As it has been previously mentioned, this research on borders is also used to rethink the discussion about an ethics of architecture and to argue that it is necessary to recognize that performativity and violence are intrinsic to architecture in order to develop such an ethics. Finally, this PhD Thesis develops artistic practice not only as one of its topics, but also as a research methodology with the aim of stressing the epistemological importance of the arts.Esta tesis examina el modo en el que la arquitectura opera, cómo se relaciona con prácticas artísticas, y cuáles son las posibilidades para desarrollar una ética de la arquitectura. Como algunos autores y autoras –como Bernard Tschumi– apuntan, las estructuras arquitectónicas son intrínsecamente performativas y violentas. La arquitectura se convierte en un evento violento tan pronto como interviene en y obstruye la vida, evitando ciertos movimientos, imponiendo coreografías o impidiendo el acceso a ciertos espacios, por ejemplo. Así, la arquitectura condiciona y restringe el mundo. La frontera es el paisaje elegido para teorizar sobre esta performatividad y violencias inherentes a la arquitectura. Dos contextos de frontera específicos serán discutidos con el objetivo de analizar el modo en el que el espacio se produce: Cisjordania, en Palestina, y Sáhara Occidental. Estos paisajes de frontera son abordados en relación con otros paisajes de frontera: las dos vallas de Ceuta y Melilla, el muro que separa EEUU de México y las vallas que están siendo construidas en Europa para afrontar la crisis de refugiadas. El objetivo en prestar atención a estas estructuras fronterizas tan diferentes es analizar las similitudes que pueda haber entre ellas y discutir hasta qué punto todas ellas funcionan de un modo semejante como parte del mismo tipo de estrategias de gestión sociopolítica. Por otro lado, analizar las interacciones entre fronteras y cuerpos permitirá centrar la atención en las formas de resistencia y re-apropiación que tienen lugar en estos contextos fronterizos. De este modo, esta tesis explora el potencial de las práctica artísticas para intervenir en las fronteras de Palestina y Sáhara Occidental. Como ha sido apuntado previamente, esta investigación sobre fronteras también sirve para repensar el debate acerca de una ética de la arquitectura y para sostener que es necesario reconocer que la arquitectura es intrínsecaemte performativa y violenta para desarrollar dicha ética. Finalmente, esta tesis desarrolla las prácticas artísicas no solo como uno de sus temas, sino también como metodología de investigación con el objetivo de enfatizar la importancia epistemológica de las artes

Improving star cluster age estimates in PHANGS-HST galaxies and the impact on cluster demographics in NGC 628

We thank the referee for several useful and constructive comments that lead to improvements in the paper. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained from the data archive at the Space Telescope Science Institute. STScI is operated by the Association of Universities for Research in Astronomy, Inc. under NASA contract NAS 5-26555. Support for Program number 15654 was provided through a grant from the STScI under NASA contract NAS5-26555. FB and AB would like to acknowledge funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement No.726384/Empire). MB gratefully acknowledges support by the ANID BASAL project FB210003 and from the FONDECYT regular grant 1211000. EW acknowledges support from the DFG via SFB 881 ‘The Milky Way System’ (project-ID 138713538; subproject P01). FB acknowledges funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement No.726384/Empire). HAP acknowledges support by the National Science and Technology Council of Taiwan under grant 110-2112-M-032-020-MY3. JMDK acknowledges funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme via the ERC Starting Grant MUSTANG (grant agreement number 714907). COOL Research DAO is a Decentralised Autonomous Organisation supporting research in astrophysics aimed at uncovering our cosmic origins. KG is supported by the Australian Research Council through the Discovery Early Career Researcher Award (DECRA) Fellowship DE220100766 funded by the Australian Government. KK and FS gratefully acknowledge funding from the German Research Foundation (DFG) in the form of an Emmy Noether Research Group (grant No. KR4598/2-1, PI Kreckel). PSB acknowledges financial support from the Spanish Ministry of Science, Innovation and Universities under grant number PID2019-107427GB-C31. RSK and MCS are thankful for support from the Deutsche Forschungsgemeinschaft (DFG) via the Collaborative Research Center (SFB 881, ProjectID 138713538) “The Milky Way System” (sub-projects A1, B1, B2 and B8) and from the Heidelberg Cluster of Excellence (EXC 2181 - 390900948) “STRUCTURES: A unifying approach to emergent phenomena in the physical world, mathematics, and complex data”, funded by the German Excellence Strategy. RSK and MSC also acknowledge funding from the European Research Council in the ERC Synergy Grant “ECOGAL – Understanding our Galactic ecosystem: From the disk of the Milky Way to the formation sites of stars and planets” (project ID 855130). TGW acknowledges funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement No. 694343).A long-standing problem when deriving the physical properties of stellar populations is the degeneracy between age, reddening, and metallicity. When a single metallicity is used for all the star clusters in a galaxy, this degeneracy can result in 'catastrophic' errors for old globular clusters. Typically, approximately 10-20 per cent of all clusters detected in spiral galaxies can have ages that are incorrect by a factor of 10 or more. In this paper, we present a pilot study for four galaxies (NGC 628, NGC 1433, NGC 1365, and NGC 3351) from the PHANGS-HST survey. We describe methods to correct the age-dating for old globular clusters, by first identifying candidates using their colours, and then reassigning ages and reddening based on a lower metallicity solution. We find that young 'Interlopers' can be identified from their H alpha flux. CO (2-1) intensity or the presence of dust can also be used, but our tests show that they do not work as well. Improvements in the success fraction are possible at the approximate to 15 per cent level (reducing the fraction of catastrophic age-estimates from between 13 and 21 per cent, to between 3 and 8 per cent). A large fraction of the incorrectly age-dated globular clusters are systematically given ages around 100 Myr, polluting the younger populations as well. Incorrectly age-dated globular clusters significantly impact the observed cluster age distribution in NGC 628, which affects the physical interpretation of cluster disruption in this galaxy. For NGC 1365, we also demonstrate how to fix a second major age-dating problem, where very dusty young clusters with E(B - V) > 1.5 mag are assigned old, globular-cluster like ages. Finally, we note the discovery of a dense population of approximate to 300 Myr clusters around the central region of NGC 1365 and discuss how this results naturally from the dynamics in a barred galaxy.Depto. de Física de la Tierra y AstrofísicaFac. de Ciencias FísicasTRUEAssociation of Universities for Research in Astronomy, Inc. under NASA contractEuropean Research Council (ERC) under the European Union’s Horizon 2020ANID BASALFondo Nacional de Desarrollo Científico y Tecnológico (FONDECYT)DFG via SFB 881 ‘The Milky Way System’National Science and Technology Council of TaiwanERC Starting Grant MUSTANGAustralian Research Council through the Discovery Early Career Researcher Award (DECRA)German Research Foundation (DFG)Ministerio de Ciencia, Innovación y UniversidadesDeutsche Forschungsgemeinschaft (DFG) via the Collaborative Research CenterHeidelberg Cluster of Excellence funded by the German Excellence StrategyEuropean Research Council in the ERC Synergypu

PHANGS-JWST first results: a combined HST and JWST analysis of the nuclear star cluster in NGC 628

© 2023. The Author(s). Artículo firmado por 32 autores. This research is based on observations made with the NASA/ESA Hubble Space Telescope obtained from the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 526555. These observations are associated with program 15654. This work is based on observations made with the NASA/ESA/CSA JWST. The data were obtained from the Mikulski Archive for Space Telescopes at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-03127. The observations are associated with JWST program 02107. This research has made use of the Spanish Virtual Observatory (https://svo.cab.intacsic.es) project funded by MCIN/AEI/10.13039/ 501100011033/ through grant PID2020-112949GB-I00. N.H. and A.W.H.K. are fellows of the International Max Planck Research School for Astronomy and Cosmic Physics at the University of Heidelberg (IMPRS-HD) and acknowledge their support. N.H. acknowledges support from Thomas Müller (HdA/MPIA) with generating part of Figure 1 and Katja Fahrion and Torsten Böker for useful discussions. A.T.B. and F.B. would like to acknowledge funding from the European Research Council (ERC) under the European Unionʼs Horizon 2020 research and innovation program (grant agreement No. 726384/Empire). E.J.W. acknowledges the funding provided by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation)—Project-ID 138713538—SFB 881 (“The Milky Way System,” subproject P1) T.G.W. and J.N. acknowledge funding from the European Research Council (ERC) under the European Unionʼs Horizon 2020 research and innovation program (grant agreement No. 694343). J.M.D.K. gratefully acknowledges funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation program via the ERC Starting Grant MUSTANG (grant agreement No. 714907). COOL Research DAO is a Decentralized Autonomous Organization supporting research in astrophysics aimed at uncovering our cosmic origins. R.S.K. acknowledges funding from the European Research Council via the ERC Synergy Grant “ECOGAL” (project ID 855130), the Deutsche Forschungsgemeinschaft (DFG) via the Collaborative Research Center “The Milky Way System” (SFB 881—funding ID 138713538—subprojects A1, B1, B2 and B8), and the Heidelberg Cluster of Excellence (EXC 2181-390900948) “STRUCTURES,” funded by the German Excellence Strategy. R.S.K. also thanks the German Ministry for Economic Affairs and Climate Action for funding in the project “MAINN” (funding ID 50OO2206). E.R. acknowledges the support of the Natural Sciences and Engineering Research Council of Canada (NSERC), funding reference No. RGPIN-2022-03499. M.B. acknowledges support from FONDECYT regular grant 1211000 and by ANID BASAL project FB210003. K.G. is supported by the Australian Research Council through the Discovery Early Career Researcher Award (DECRA) Fellowship DE220100766 funded by the Australian Government. K.G. is supported by the Australian Research Council Centre of Excellence for All Sky Astrophysics in 3 Dimensions (ASTRO 3D) through project No. CE170100013. F.N.-L. gratefully acknowledges the sponsorship provided by the Federal Ministry for Education and Research of Germany through the Alexander von Humboldt Foundation. P.S.B. acknowledges financial support from MCIN/AEI/10.13039/501100011033 under grant PID2019-107427GB-C31 A.K.L. gratefully acknowledges support by grants 1653300 and 2205628 from the National Science Foundation, award JWST-GO-02107.009-A, and a Humboldt Research Award from the Alexander von Humboldt Foundation. G.A.B. acknowledges the support from ANID Basal project FB210003.We combine archival Hubble Space Telescope and new James Webb Space Telescope imaging data covering the ultraviolet to mid-infrared regime to morphologically analyze the nuclear star cluster (NSC) of NGC 628, a granddesign spiral galaxy. The cluster is located in a 200 pc × 400 pc cavity lacking both dust and gas. We find roughly constant values for the effective radius (r_(eff) ∼ 5 pc) and ellipticity (∈ ∼ 0.05), while the Sérsic index (n) and position angle (PA) drop from n ∼ 3 to ∼2 and PA ∼ 130° to 90°, respectively. In the mid-infrared, r_(eff) ∼ 12 pc, ∈ ∼ 0.4, and n ∼ 1–1.5, with the same PA ∼ 90°. The NSC has a stellar mass of log_(10) (M^(nsc)_(*) / M_(ꙩ) = 7.06 0.31, as derived through B − V, confirmed when using multiwavelength data, and in agreement with the literature value. Fitting the spectral energy distribution (SED), excluding the mid-infrared data, yields a main stellar population age of (8 ± 3) Gyr with a metallicity of Z = 0.012 ± 0.006. There is no indication of any significant star formation over the last few gigayears. Whether gas and dust were dynamically kept out or evacuated from the central cavity remains unclear. The best fit suggests an excess of flux in the mid-infrared bands, with further indications that the center of the mid-infrared structure is displaced with respect to the optical center of the NSC. We discuss five potential scenarios, none of them fully explaining both the observed photometry and structure.Depto. de Física de la Tierra y AstrofísicaFac. de Ciencias FísicasTRUEAssociation of Universities for Research in Astronomy, Inc., under NASA contractAssociation of Universities for Research in Astronomy, Inc., under NASA contractSpanish Virtual Observatory funded by MCIN/AEI/10.13039/ 501100011033/International Max Planck Research School for Astronomy and Cosmic Physics at the University of Heidelberg (IMPRS-HD)Thomas Müller (HdA/MPIA)European Research Council (ERC) under the European Unionʼs Horizon 2020Deutsche Forschungsgemeinschaft (DFG, German Research Foundation)European Research Council via the ERC SynergyDeutsche Forschungsgemeinschaft (DFG) via the Collaborative Research Center “The Milky Way System”Heidelberg Cluster of Excellence “STRUCTURES,” funded by the German Excellence StrategyGerman Ministry for Economic Affairs and Climate ActionNatural Sciences and Engineering Research Council of Canada (NSERC)Australian Research Council through the Discovery Early Career Researcher Award (DECRA)Australian Research Council Centre of Excellence for All Sky Astrophysics in 3 Dimensions (ASTRO 3D)Federal Ministry for Education and Research of Germany through the Alexander von Humboldt FoundationMCIN/AEI/10.13039/501100011033National Science FoundationAlexander von Humboldt FoundationANID Basal projectpu

Exploring the Star Formation History of Elliptical Galaxies: Beyond Simple Stellar Populations with a New Estimator of Line Strengths

(Abridged) We study the stellar populations of 14 elliptical galaxies in the Virgo cluster. We propose an alternative approach to the standard side-band method to measure equivalent widths (EWs). Our Boosted Median Continuum maps the EWs more robustly than the side-band method, minimising the effect from neighbouring absorption lines and reducing the age-metallicity degeneracy. We concentrate on Balmer lines (Hbeta,Hgamma,Hdelta), the G band and the 4000A break as age-sensitive indicators, and on the combination [MgFe] as the main metallicity indicator. We go beyond the standard comparison of the observations with simple stellar populations (SSP) and consider various models to describe the star formation histories, either with a continuous star formation rate or with a mixture of two different SSPs. Composite models are found to give more consistent fits among individual line strengths and agree with an independent estimate using the spectral energy distribution. Our age and metallicity estimates correlate well with stellar mass or velocity dispersion, with a significant threshold around 5E10 Msun above which galaxies are uniformly old and metal rich. In a more speculative way, our models suggest that it is formation **epoch** and not formation timescale what drives the Mass-Age relationship of elliptical galaxies.Comment: 15 pages, 15 figures, 4 tables. Accepted for publication in MNRA

NH and Mg Index Trends in Elliptical Galaxies

We examine the spectrum in the vicinity of the NH3360 index of Davidge & Clark (1994), which was defined to measure the NH absorption around 3360 \AA and which shows almost no trend with velocity dispersion (Toloba et al. 2009), unlike other N- sensitive indices, which show a strong trend (Graves et al. 2007). Computing the effect of individual elements on the integrated spectrum with synthetic stellar population integrated spectra, we find that, while being well correlated with nitrogen abundance, NH3360 is almost equally well anti-correlated with Mg abundance. This prompts the definition of two new indices, Mg3334, which is mostly sensitive to magnesium, and NH3375, which is mostly sensitive to nitrogen. Rather surprisingly, we find that the new NH3375 index shows a trend versus optical absorption feature indices that is as shallow as the NH3360 index. We hypothesize that the lack of a strong index trend in these near-UV indices is due to the presence of an old metal-poor component of the galactic population. Comparison of observed index trends and those predicted by models shows that a modest fraction of an old, metal-poor stellar population could easily account for the observed flat trend in these near-UV indices, while still allowing substantial N abundance increase in the larger galaxies.Comment: 19 pages, 6 figures, 6 table

Gz mediates the long-lasting desensitization of brain CB1 receptors and is essential for cross-tolerance with morphine

Abstract Background Although the systemic administration of cannabinoids produces antinociception, their chronic use leads to analgesic tolerance as well as cross-tolerance to morphine. These effects are mediated by cannabinoids binding to peripheral, spinal and supraspinal CB1 and CB2 receptors, making it difficult to determine the relevance of each receptor type to these phenomena. However, in the brain, the CB1 receptors (CB1Rs) are expressed at high levels in neurons, whereas the expression of CB2Rs is marginal. Thus, CB1Rs mediate the effects of smoked cannabis and are also implicated in emotional behaviors. We have analyzed the production of supraspinal analgesia and the development of tolerance at CB1Rs by the direct injection of a series of cannabinoids into the brain. The influence of the activation of CB1Rs on supraspinal analgesia evoked by morphine was also evaluated. Results Intracerebroventricular (icv) administration of cannabinoid receptor agonists, WIN55,212-2, ACEA or methanandamide, generated a dose-dependent analgesia. Notably, a single administration of these compounds brought about profound analgesic tolerance that lasted for more than 14 days. This decrease in the effect of cannabinoid receptor agonists was not mediated by depletion of CB1Rs or the loss of regulated G proteins, but, nevertheless, it was accompanied by reduced morphine analgesia. On the other hand, acute morphine administration produced tolerance that lasted only 3 days and did not affect the CB1R. We found that both neural mu-opioid receptors (MORs) and CB1Rs interact with the HINT1-RGSZ module, thereby regulating pertussis toxin-insensitive Gz proteins. In mice with reduced levels of these Gz proteins, the CB1R agonists produced no such desensitization or morphine cross-tolerance. On the other hand, experimental enhancement of Gz signaling enabled an acute icv administration of morphine to produce a long-lasting tolerance at MORs that persisted for more than 2 weeks, and it also impaired the analgesic effects of cannabinoids. Conclusion In the brain, cannabinoids can produce analgesic tolerance that is not associated with the loss of surface CB1Rs or their uncoupling from regulated transduction. Neural specific Gz proteins are essential mediators of the analgesic effects of supraspinal CB1R agonists and morphine. These Gz proteins are also responsible for the long-term analgesic tolerance produced by single doses of these agonists, as well as for the cross-tolerance between CB1Rs and MORs.</p

Constraints to dark matter annihilation from high-latitude hawc unidentified sources

The ΛCDM cosmological framework predicts the existence of thousands of subhalos in our own Galaxy not massive enough to retain baryons and become visible. Yet, some of them may outshine in gamma rays provided that the dark matter is made of weakly interacting massive particles (WIMPs), which would self-annihilate and would appear as unidentified gamma-ray sources (unIDs) in gamma-ray catalogs. Indeed, unIDs have proven to be competitive targets for dark matter searches with gamma rays. In this work, we focus on the three high-latitude (|b| ≥ 10) sources present in the 2HWC catalog of the High Altitude Water Cherenkov (HAWC) observatory with no clear associations at other wavelengths. Indeed, only one of these sources, 2HWC J1040+308, is found to be above the HAWC detection threshold when considering 760 days of data, i.e., a factor 1.5 more exposure time than in the original 2HWC catalog. Other gamma-ray instruments, such as Fermi-LAT or VERITAS at lower energies, do not detect the source. Also, this unID is reported as spatially extended, making it even more interesting in a dark matter search context. While waiting for more data that may shed further light on the nature of this source, we set competitive upper limits on the annihilation cross section by comparing this HAWC unID to expectations based on state-of-the-art N-body cosmological simulations of the Galactic subhalo population. We find these constraints to be particularly competitive for heavy WIMPs, i.e., masses above ∼25 (40) TeV in the case of the b ¯b (τ +τ −) annihilation channel, reaching velocity-averaged cross section values of 2 × 10−25 (5 × 10−25) cm3 ·s −1 . Although far from testing the thermal relic cross section value, the obtained limits are independent and nicely complementary to those from radically different DM analyses and targets, demonstrating once again the high potential of this DM search approachJ.C.-B. and M.A.S.-C. are supported by the Atracción de Talento contract no. 2016-T1/TIC-1542 granted by the Comunidad de Madrid in Spain, by the Spanish Agencia Estatal de Investigación through the grants PGC2018-095161-B-I00, IFT Centro de Excelencia Severo Ochoa SEV-2016-0597, and Red Consolider MultiDark FPA2017-90566-RED

The role of stellar radial motions in shaping galaxy surface brightness profiles

Aims. The physics driving features such as breaks observed in galaxy surface brightness (SB) profiles remains contentious. Here, we assess the importance of stellar radial motions in shaping their characteristics. Methods. We use the simulated Milky Way-mass cosmological discs from the Ramses Disc Environment Study (RaDES) to characterise the radial redistribution of stars in galaxies displaying type-I (pure exponentials), II (downbending), and III (upbending) SB profiles. We compare radial profiles of the mass fractions and the velocity dispersions of different sub-populations of stars according to their birth and current location. Results. Radial redistribution of stars is important in all galaxies regardless of their light profiles. Type-II breaks seem to be a consequence of the combined effects of outward-moving and accreted stars. The former produce shallower inner profiles (lack of stars in the inner disc) and accumulate material around the break radius and beyond, strengthening the break; the latter can weaken or even convert the break into a pure exponential. Further accretion from satellites can concentrate material in the outermost parts, leading to type-III breaks that can coexist with type-II breaks, but situated further out. Type-III galaxies would be the result of an important radial redistribution of material throughout the entire disc, as well as a concentration of accreted material in the outskirts. In addition, type-III galaxies display the most efficient radial redistribution and the largest number of accreted stars, followed by type-I and II systems, suggesting that type-I galaxies may be an intermediate case between types-II and III. In general, the velocity dispersion profiles of all galaxies tend to flatten or even increase around the locations where the breaks are found. The age and metallicity profiles are also affected, exhibiting different inner gradients depending on their SB profile, being steeper in the case of type-II systems (as found observationally). The steep type-II profiles might be inherent to their formation rather than acquired via radial redistribution