118 research outputs found
Conflict of Interest: A Totally Ignored Illinois Criminal Sanction against Corruption in Government
Dismay, Dissembly and Geocide:Ways Through the Maze of Trumpist Geopolitics
Written in the still-unfolding aftermath of Donald Trump's accession to the office of President of the United States, this article picks up and expands upon some of the key points raised by Kyle McGee's Heathen Earth, particularly concerning the forms of political violence emergent in an age ever-increasingly defined by climate change and the strategies of analysis, theorisation and critique that these geohistorical developments demand. Much like McGee's book, it takes a particularly troubling contemporary political event as a spur to develop thoughts deriving from more long-term projects concerning the way we have come to divide up the world and the manner in which these divisions are contestedpublishersversionNon peer reviewe
Evolution of dynamic fibrils from the cooler chromosphere to the hotter corona
Dynamic fibrils (DFs) are commonly observed chromospheric features in solar
active regions. Recent observations from the Extreme Ultraviolet Imager (EUI)
aboard the Solar Orbiter have revealed unambiguous signatures of DFs at the
coronal base, in extreme ultraviolet (EUV) emission. However, it remains
unclear if the DFs detected in the EUV are linked to their chromospheric
counterparts. Simultaneous detection of DFs from chromospheric to coronal
temperatures could provide important information on their thermal structuring
and evolution through the solar atmosphere. In this paper, we address this
question by using coordinated EUV observations from the Atmospheric Imaging
Assembly (AIA), Interface Region Imaging Spectrograph (IRIS), and EUI to
establish a one-to-one correspondence between chromospheric and transition
region DFs (observed by IRIS) with their coronal counterparts (observed by EUI
and AIA). Our analysis confirms a close correspondence between DFs observed at
different atmospheric layers, and reveals that DFs can reach temperatures of
about 1.5 million Kelvin, typical of the coronal base in active regions.
Furthermore, intensity evolution of these DFs, as measured by tracking them
over time, reveals a shock-driven scenario in which plasma piles up near the
tips of these DFs and, subsequently, these tips appear as bright blobs in
coronal images. These findings provide information on the thermal structuring
of DFs and their evolution and impact through the solar atmosphere.Comment: Accepted for publication in A&A Letters. Animation files are
available
https://drive.google.com/drive/folders/17-fqQz_P2T18llJ1jB6MJISMRvT5063F?usp=sharin
Evolution of dynamic fibrils from the cooler chromosphere to the hotter corona
Dynamic fibrils (DFs) are commonly observed chromospheric features in solar active regions. Recent observations from the Extreme Ultraviolet Imager (EUI) aboard the Solar Orbiter have revealed unambiguous signatures of DFs at the coronal base in extreme ultraviolet (EUV) emission. However, it remains unclear if the DFs detected in the EUV are linked to their chromospheric counterparts. Simultaneous detection of DFs from chromospheric to coronal temperatures could provide important information on their thermal structuring and evolution through the solar atmosphere. In this paper, we address this question by using coordinated EUV observations from the Atmospheric Imaging Assembly (AIA), Interface Region Imaging Spectrograph (IRIS), and EUI to establish a one-to-one correspondence between chromospheric and transition region DFs (observed by IRIS) with their coronal counterparts (observed by EUI and AIA). Our analysis confirms a close correspondence between DFs observed at different atmospheric layers and reveals that DFs can reach temperatures of about 1.5 million Kelvin, typical of the coronal base in active regions. Furthermore, the intensity evolution of these DFs, as measured by tracking them over time, reveals a shock-driven scenario in which plasma piles up near the tips of these DFs and, subsequently, these tips appear as bright blobs in coronal images. These findings provide information on the thermal structuring of DFs and their evolution and impact through the solar atmosphere
Signatures of dynamic fibrils at the coronal base: Observations from Solar Orbiter/EUI
The solar chromosphere hosts a wide variety of transients, including dynamic
fibrils (DFs) that are characterised as elongated, jet-like features seen in
active regions, often through H diagnostics. So far, these features
have been difficult to identify in coronal images primarily due to their small
size and the lower spatial resolution of the current EUV imagers. Here we
present the first unambiguous signatures of DFs in coronal EUV data using
high-resolution images from the Extreme Ultraviolet Imager (EUI) on board Solar
Orbiter. Using the data acquired with the 174~{\AA} High Resolution Imager
(HRI) of EUI, we find many bright dot-like features (of size 0.3-0.5
Mm) that move up and down (often repeatedly) in the core of an active region.
In a space-time map, these features produce parabolic tracks akin to the
chromospheric observations of DFs. Properties such as their speeds (14
km~s), lifetime (332~s), deceleration (82 m~s) and lengths
(1293~km) are also reminiscent of the chromospheric DFs. The EUI data strongly
suggest that these EUV bright dots are basically the hot tips (of the cooler
chromospheric DFs) that could not be identified unambiguously before because of
a lack of spatial resolution.Comment: Accepted for publication in A&A Letters. Event movie can be
downloaded from
https://drive.google.com/file/d/1o_4jHA5JbyQtrpUBtB3ItE_s3HjF6ncc/view?usp=sharin
Dissociation of virtual photons in events with a leading proton at HERA
The ZEUS detector has been used to study dissociation of virtual photons in
events with a leading proton, gamma^* p -> X p, in e^+p collisions at HERA. The
data cover photon virtualities in two ranges, 0.03<Q^2<0.60 GeV^2 and 2<Q^2<100
GeV^2, with M_X>1.5 GeV, where M_X is the mass of the hadronic final state, X.
Events were required to have a leading proton, detected in the ZEUS leading
proton spectrometer, carrying at least 90% of the incoming proton energy. The
cross section is presented as a function of t, the squared four-momentum
transfer at the proton vertex, Phi, the azimuthal angle between the positron
scattering plane and the proton scattering plane, and Q^2. The data are
presented in terms of the diffractive structure function, F_2^D(3). A
next-to-leading-order QCD fit to the higher-Q^2 data set and to previously
published diffractive charm production data is presented
Alignment of the CMS silicon tracker during commissioning with cosmic rays
This is the Pre-print version of the Article. The official published version of the Paper can be accessed from the link below - Copyright @ 2010 IOPThe CMS silicon tracker, consisting of 1440 silicon pixel and 15 148 silicon strip detector modules, has been aligned using more than three million cosmic ray charged particles, with additional information from optical surveys. The positions of the modules were determined with respect to cosmic ray trajectories to an average precision of 3â4 microns RMS in the barrel and 3â14 microns RMS in the endcap in the most sensitive coordinate. The results have been validated by several studies, including laser beam cross-checks, track fit self-consistency, track residuals in overlapping module regions, and track parameter resolution, and are compared with predictions obtained from simulation. Correlated systematic effects have been investigated. The track parameter resolutions obtained with this alignment are close to the design performance.This work is supported by FMSR (Austria); FNRS and FWO (Belgium); CNPq, CAPES, FAPERJ,
and FAPESP (Brazil); MES (Bulgaria); CERN; CAS, MoST, and NSFC (China); COLCIENCIAS
(Colombia); MSES (Croatia); RPF (Cyprus); Academy of Sciences and NICPB (Estonia);
Academy of Finland, ME, and HIP (Finland); CEA and CNRS/IN2P3 (France); BMBF, DFG,
and HGF (Germany); GSRT (Greece); OTKA and NKTH (Hungary); DAE and DST (India); IPM (Iran); SFI (Ireland); INFN (Italy); NRF (Korea); LAS (Lithuania); CINVESTAV, CONACYT,
SEP, and UASLP-FAI (Mexico); PAEC (Pakistan); SCSR (Poland); FCT (Portugal); JINR (Armenia, Belarus, Georgia, Ukraine, Uzbekistan); MST and MAE (Russia); MSTDS (Serbia); MICINN and CPAN (Spain); Swiss Funding Agencies (Switzerland); NSC (Taipei); TUBITAK and TAEK (Turkey); STFC (United Kingdom); DOE and NSF (USA)
Commissioning and performance of the CMS pixel tracker with cosmic ray muons
This is the Pre-print version of the Article. The official published verion of the Paper can be accessed from the link below - Copyright @ 2010 IOPThe pixel detector of the Compact Muon Solenoid experiment consists of three barrel layers and two disks for each endcap. The detector was installed in summer 2008, commissioned with charge injections, and operated in the 3.8 T magnetic field during cosmic ray data taking. This paper reports on the first running experience and presents results on the pixel tracker performance, which are found to be in line with the design specifications of this detector. The transverse impact parameter resolution measured in a sample of high momentum muons is 18 microns.This work is supported by FMSR (Austria); FNRS and FWO (Belgium); CNPq, CAPES, FAPERJ,
and FAPESP (Brazil); MES (Bulgaria); CERN; CAS, MoST, and NSFC (China); COLCIENCIAS (Colombia); MSES (Croatia); RPF (Cyprus); Academy of Sciences and NICPB (Estonia);
Academy of Finland, ME, and HIP (Finland); CEA and CNRS/IN2P3 (France); BMBF, DFG,
and HGF (Germany); GSRT (Greece); OTKA and NKTH (Hungary); DAE and DST (India); IPM (Iran); SFI (Ireland); INFN (Italy); NRF (Korea); LAS (Lithuania); CINVESTAV, CONACYT,
SEP, and UASLP-FAI (Mexico); PAEC (Pakistan); SCSR (Poland); FCT (Portugal); JINR (Armenia, Belarus, Georgia, Ukraine, Uzbekistan); MST and MAE (Russia); MSTDS (Serbia); MICINN and CPAN (Spain); Swiss Funding Agencies (Switzerland); NSC (Taipei); TUBITAK and TAEK (Turkey); STFC (United Kingdom); DOE and NSF (USA)
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