La reconversion des friches militaires urbaines dans les années 2000 : une opportunité pour Mulhouse ?

Alors que la ville, autrefois gourmande d’espace foncier sur ses franges, s’efforce aujourd’hui de rationaliser sa trame urbaine dans une logique de développement durable, elle s’intéresse davantage à ses espaces délaissés. Parmi ces sites en attente de reconversion, les fiches militaires offrent de réelles opportunités de requalification et participent ainsi au renouvellement urbain. Cet article propose notamment d’envisager l’éventuelle spécificité de ces friches tout en complétant des notions déjà connus sur le foncier en attente de requalification. Le terrain d’étude de Mulhouse, avec trois casernes reconverties, sera ensuite analysé afin d’illustrer ces éléments.In the past, the city used easily the land space on its fringes. While it is today trying to rationalize the urban network in the frame of sustainable development, it is more interested in its derelict lands and it tries to set up a frame of urban regeneration, which could be applied to all these wastelands. Among these waiting for renewal sites, the urban military brownfields could give real opportunities as part of urban regeneration and so participate to the urban renewal. This article proposes to consider the possible specificities of these brownfields while complementing already known notions about the waiting for requalification lands. The city of Mulhouse with three converted barracks will then be analyzed to illustrate these elements.Die Stadt war früher raumsgierig auf ihren Fransen aber heute versucht sie in einer Logik der dauerhaften Entwicklung, den Stadteinschlag, zu straffen. Sie interessiert sich doch mehr für ihre verlassenen Räume. Unter diesen in der Requalifizierungerwartung Gegenden bieten die militärische Ödländer wirkliche Wiedernutzbarmachung für die Stadterneuerung an. Dieser Artikel schlägt insbesondere die Mögliche Spezifität dieser Ödländer vor, während bereits bekannte Konzepte auf dem Land zur Requalifikation abgeschlossen werden. Das Studiengelände von Mulhouse mit drei umgebauten Baracken wird dann analysiert, um diese Elemente zu veranschaulichen

The Arizona CDFS Environment Survey (ACES): A Magellan/IMACS Spectroscopic Survey of the Chandra Deep Field-South

We present the Arizona CDFS Environment Survey (ACES), a recently-completed spectroscopic redshift survey of the Chandra Deep Field South (CDFS) conducted using IMACS on the Magellan-Baade telescope. In total, the survey targeted 7277 unique sources down to a limiting magnitude of R = 24.1, yielding 5080 secure redshifts across the ~30' x 30' extended CDFS region. The ACES dataset delivers a significant increase to both the spatial coverage and the sampling density of the spectroscopic observations in the field. Combined with previously-published, spectroscopic redshifts, ACES now creates a highly-complete survey of the galaxy population at R < 23, enabling the local galaxy density (or environment) on relatively small scales (~1 Mpc) to be measured at z < 1 in one of the most heavily-studied and data-rich fields in the sky. Here, we describe the motivation, design, and implementation of the survey and present a preliminary redshift and environment catalog. In addition, we utilize the ACES spectroscopic redshift catalog to assess the quality of photometric redshifts from both the COMBO-17 and MUSYC imaging surveys of the CDFS.Comment: resubmitted to MNRAS; 12 pages, 12 figures, and 3 tables; updated redshift catalog available at http://mur.ps.uci.edu/~cooper/ACES

The DEEP3 Galaxy Redshift Survey: Keck/DEIMOS Spectroscopy in the GOODS-N Field

We present the results of spectroscopic observations in the GOODS-N field completed using DEIMOS on the Keck II telescope as part of the DEEP3 Galaxy Redshift Survey. Observations of 370 unique targets down to a limiting magnitude of R = 24.4 yielded 156 secure redshifts. In addition to redshift information, we provide sky-subtracted one- and two-dimensional spectra of each target. Observations were conducted following the procedures of the Team Keck Redshift Survey (TKRS), thereby producing spectra that augment the TKRS sample while maintaining the uniformity of its spectral database.Comment: Accepted for publication in ApJS; 5 Pages, 2 Figures; Redshift Catalog and Spectra available at http://deep.berkeley.edu/GOODSN

No More Active Galactic Nuclei in Clumpy Disks than in Smooth Galaxies at \u3cem\u3ez\u3c/em\u3e ~ 2 in CANDELS/3D-HST*

We use CANDELS imaging, 3D-HST spectroscopy, and Chandra X-ray data to investigate if active galactic nuclei (AGNs) are preferentially fueled by violent disk instabilities funneling gas into galaxy centers at 1.3 \u3c z \u3c 2.4. We select galaxies undergoing gravitational instabilities using the number of clumps and degree of patchiness as proxies. The CANDELS visual classification system is used to identify 44 clumpy disk galaxies, along with mass-matched comparison samples of smooth and intermediate morphology galaxies. We note that despite being mass-matched and having similar star formation rates, the smoother galaxies tend to be smaller disks with more prominent bulges compared to the clumpy galaxies. The lack of smooth extended disks is probably a general feature of the z ~ 2 galaxy population, and means we cannot directly compare with the clumpy and smooth extended disks observed at lower redshift. We find that z ~ 2 clumpy galaxies have slightly enhanced AGN fractions selected by integrated line ratios (in the mass-excitation method), but the spatially resolved line ratios indicate this is likely due to extended phenomena rather than nuclear AGNs. Meanwhile, the X-ray data show that clumpy, smooth, and intermediate galaxies have nearly indistinguishable AGN fractions derived from both individual detections and stacked non-detections. The data demonstrate that AGN fueling modes at z ~ 1.85—whether violent disk instabilities or secular processes—are as efficient in smooth galaxies as they are in clumpy galaxies

The Physical Conditions of Emission-Line Galaxies at Cosmic Dawn from JWST/NIRSpec Spectroscopy in the SMACS 0723 Early Release Observations

We present rest-frame optical emission-line flux ratio measurements for five $z>5$ galaxies observed by the JWST Near-Infared Spectrograph (NIRSpec) in the SMACS 0723 Early Release Observations. We add several quality-control and post-processing steps to the NIRSpec pipeline reduction products in order to ensure reliable relative flux calibration of emission lines that are closely separated in wavelength, despite the uncertain \textit{absolute} spectrophotometry of the current version of the reductions. Compared to $z\sim3$ galaxies in the literature, the $z>5$ galaxies have similar [OIII]$\lambda$5008/H$\beta$ ratios, similar [OIII]$\lambda$4364/H$\gamma$ ratios, and higher ($\sim$0.5 dex) [NeIII]$\lambda$3870/[OII]$\lambda$3728 ratios. We compare the observations to MAPPINGS V photoionization models and find that the measured [NeIII]$\lambda$3870/[OII]$\lambda$3728, [OIII]$\lambda$4364/H$\gamma$, and [OIII]$\lambda$5008/H$\beta$ emission-line ratios are consistent with an interstellar medium that has very high ionization ($\log(Q) \simeq 8-9$, units of cm~s$^{-1}$), low metallicity ($Z/Z_\odot \lesssim 0.2$), and very high pressure ($\log(P/k) \simeq 8-9$, units of cm$^{-3}$). The combination of [OIII]$\lambda$4364/H$\gamma$ and [OIII]$\lambda$(4960+5008)/H$\beta$ line ratios indicate very high electron temperatures of $4.1<\log(T_e/{\rm K})<4.4$, further implying metallicities of $Z/Z_\odot \lesssim 0.2$ with the application of low-redshift calibrations for ``$T_e$-based'' metallicities. These observations represent a tantalizing new view of the physical conditions of the interstellar medium in galaxies at cosmic dawn.Comment: Accepted for publication in AAS Journals. 14 pages, 6 figures, 3 table

L'effet de levier dans la reconversion des friches militaires dans le cadre du renouvellement urbain en France

In a context of general reform of public policies and of adaptation of the tool of Defence to new geostrategical pressures, Military brownfields are growing.In the past, the city used easily the land space on its fringes. While it is today trying to rationalize the urban network in the frame of sustainable development, it is more interested in its derelict lands and it tries to set up a logic of urban regeneration which could be applied to all these wastelands, whatever is the nature of their initial activities. Among these waiting of renewal sites, the urban military wastelands could give real opportunities as part of regeneration and so participate to the urban renewal.The objective of this thesis is twofold: It is to consider how the military urban brownfields can be unmarked since their initial activity has ceased. Then, by reading the results of the regeneration with the fourth time of wastelands, it is about to determine if the regeneration of an urban military brownfields can have a leverage effect for a city or region.Five study sites are analyzed to answer these questionsDans un contexte de réforme générale des politiques publiques et d’adaptation de l’outil de Défense aux nouvelles contraintes géostratégiques, Les friches militaires sont de plus en plus nombreuses.Alors que la ville, autrefois gourmande d’espace foncier sur ses franges, s’efforce aujourd’hui de rationnaliser la trame urbaine dans une logique de développement durable, elle s’intéresse davantage à ses espaces délaissés et tente de mettre en place une logique de reconversion qui puisse s’appliquer toutes ces friches, quelle que soit la nature de leurs activités initiales. Parmi ces sites en attente de reconversion, les fiches militaires urbaines pourraient offrir de réelles opportunités dans le cadre de r requalification et ainsi participer au renouvellement urbain.L’objectif de ce travail est double : il s’agit d’envisager dans quelle mesure la friche militaire urbaine peut être banalisée dès lors que son activité initiale a cessé. Ensuite, à la lecture des résultats de la reconversion dans le cadre d’un quatrième temps de la friche, il s’agit déterminer si la requalification d’une friche militaire urbaine peut avoir un effet levier pour une ville ou une région.Cinq terrains d’étude sont analysés afin de répondre à ces question

La reconversion des sites militaires, une opportunité pour des villes en quête d'attractivité ?

International audienc

Positiv economical effects of the reconversion of depraved military sites in France

Dans un contexte de réforme générale des politiques publiques et d’adaptation de l’outil de Défense aux nouvelles contraintes géostratégiques, Les friches militaires sont de plus en plus nombreuses.Alors que la ville, autrefois gourmande d’espace foncier sur ses franges, s’efforce aujourd’hui de rationnaliser la trame urbaine dans une logique de développement durable, elle s’intéresse davantage à ses espaces délaissés et tente de mettre en place une logique de reconversion qui puisse s’appliquer toutes ces friches, quelle que soit la nature de leurs activités initiales. Parmi ces sites en attente de reconversion, les fiches militaires urbaines pourraient offrir de réelles opportunités dans le cadre de r requalification et ainsi participer au renouvellement urbain.L’objectif de ce travail est double : il s’agit d’envisager dans quelle mesure la friche militaire urbaine peut être banalisée dès lors que son activité initiale a cessé. Ensuite, à la lecture des résultats de la reconversion dans le cadre d’un quatrième temps de la friche, il s’agit déterminer si la requalification d’une friche militaire urbaine peut avoir un effet levier pour une ville ou une région.Cinq terrains d’étude sont analysés afin de répondre à ces questionsIn a context of general reform of public policies and of adaptation of the tool of Defence to new geostrategical pressures, Military brownfields are growing.In the past, the city used easily the land space on its fringes. While it is today trying to rationalize the urban network in the frame of sustainable development, it is more interested in its derelict lands and it tries to set up a logic of urban regeneration which could be applied to all these wastelands, whatever is the nature of their initial activities. Among these waiting of renewal sites, the urban military wastelands could give real opportunities as part of regeneration and so participate to the urban renewal.The objective of this thesis is twofold: It is to consider how the military urban brownfields can be unmarked since their initial activity has ceased. Then, by reading the results of the regeneration with the fourth time of wastelands, it is about to determine if the regeneration of an urban military brownfields can have a leverage effect for a city or region.Five study sites are analyzed to answer these question

L’apparition rapide d’une friche militaire urbaine : Un joker ou une remise en question pour le projet urbain ?

International audienceThe sudden appearance of an urban military brownfield requires from the cecity to quickly consider its conversion. Opportunity, or burden, such a situation needs to agree on the fact to rethink the city in its organization and its urban development by integrating a new land space whose future functions are to be determined. It is also a question of compensating, simultaneously, the departure of the military on the economic and social levels. However, is the urban project the process that allows military brownfields to be converted in the frame of a coherent project for the benefit of the city? Field studies from the author's researches will show that if it constitutes an ideal framework, the urban project must also integrate other factors to be at the origin of the gain of attractiveness: on one hand, a finer declination of the urban project’s elements and, on the other hand, the integration of specific points that can be assimilated to elements of context.L’apparition soudaine d’une friche militaire urbaine impose à la ville concernée d’envisager rapidement sa reconversion. Opportunité, ou fardeau, une telle situation impose d’accepter de repenser la ville dans son organisation et son développement urbains en y intégrant un nouvel espace foncier dont les fonctions futures sont à déterminer. Il s’agit aussi de compenser, simultanément, le départ des militaires sur les plans économique et social. Cependant, le projet urbain est-il le processus qui permet aux friches militaires d’être reconverties dans la logique d’un projet cohérent au profit de la ville ? Des études de terrains issues des travaux de l’auteur montreront que s’il constitue un cadre idéal, le projet urbain doit aussi intégrer d’autres facteurs pour être à l’origine du gain d’attractivité : d’une part, une déclinaison plus fine de certaines composantes du projet urbain et, d’autre part, une intégration de points spécifiques assimilables à des éléments de contexte