Author: "Gomez, Jose A." / Topic: astrophysics - Searchworks@Jio Institute Digital Library Search Results

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32 results on '"Gomez, Jose A."'

1. Radio interferometric observations of candidate water-maser-emitting planetary nebulae

Author: Gomez, Jose F., Suarez, Olga, Gomez, Yolanda, Miranda, Luis F., Torrelles, Jose M., Anglada, Guillem, and Morata, Oscar
Subjects: Astrophysics
Abstract: We present Very Large Array (VLA) observations of H2O and OH masers, as well as radio continuum emission at 1.3 and 18 cm toward three sources previously cataloged as planetary nebulae (PNe) and in which single-dish detections of H2O masers have been reported: IRAS 17443-2949, IRAS 17580-3111, and IRAS 18061-2505. Our goal was to unambiguously confirm their nature as water-maser-emitting PNe, a class of objects of which only two bona-fide members were previously known. We detected and mapped H2O maser emission toward all three sources, while OH maser emission is detected in IRAS 17443-2949 and IRAS 17580-3111 as well as in other two objects within the observed fields: IRAS 17442-2942 (unknown nature) and IRAS 17579-3121 (also cataloged as a possible PN). We found radio continuum emission associated only with IRAS 18061-2505. Our results confirm IRAS 18061-2505 as the third known case of a PN associated with H2O maser emission. The three known water-maser-emitting PNe have clear bipolar morphologies, which suggests that water maser emission in these objects is related to non-spherical mass-loss episodes. We speculate that these bipolar PNe would have ``water-fountain'' Asymptotic Giant Branch (AGB) and post-AGB stars as their precursors. A note of caution is given for other objects that have been classified as OHPNe (objects with both OH maser and radio continuum emission, that could be extremely young PNe) based on single-dish observations, since interferometric data of both OH masers and continuum are necessary for a proper identification as members of this class., Comment: 33 pages, 10 figures. Accepted by The Astronomical Journal
Published: 2008
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2. Multiwaveband Polarimetric Observations of 15 Active Galactic Nuclei at High Frequencies: Correlated Polarization Behavior

Author: Jorstad, Svetlana G., Marscher, Alan P., Stevens, Jason A., Smith, Paul S., Forster, James R., Gear, Walter K., Cawthorne, Timothy V., Lister, Matthew L., Stirling, Alastair M., Gómez, José L., Greaves, Jane S., and Robson, E. Ian
Subjects: Astrophysics
Abstract: We report on multi-frequency linear polarization monitoring of 15 active galactic nuclei containing highly relativistic jets with apparent speeds from $\sim$4 $c$ to $>40c$. The measurements were obtained at optical, 1 mm, and 3 mm wavelengths, and at 7 mm with the Very Long Baseline Array. The data show a wide range in degree of linear polarization among the sources, from $<$1% to $>$30%, and interday polarization variability in individual sources. The polarization properties suggest separation of the sample into three groups with low, intermediate, and high variability of polarization in the core at 7 mm : LVP, IVP, and HVP, respectively. The groups are partially associated with the common classification of active galactic nuclei as radio galaxies and quasars with low optical polarization (LVP), BL Lacertae objects (IVP), and highly optically polarized quasars (HVP). Our study investigates correlations between total flux, fractional polarization, and polarization position angle at the different wavelengths. We interpret the polarization properties of the sources in the sample through models in which weak shocks compress turbulent plasma in the jet. The differences in the orientation of sources with respect to the observer, jet kinematics, and abundance of thermal matter external to the jet near the core can account for the diversity in the polarization properties. The results provide strong evidence that the optical polarized emission originates in shocks, most likely situated between the 3 mm and 7 mm VLBI cores. They also support the idea that the 1 mm core lies at the edge of the transition zone between electromagnetically dominated and turbulent hydrodynamical sections of the jet., Comment: 63 pages, 17 figures, 13 tables, in press AJ
Published: 2007
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3. Statistical analysis of molecular line emission from T Tauri disk models

Author: de Gregorio-Monsalvo, Itziar, D'Alessio, Paola, and Gomez, Jose F.
Subjects: Astrophysics
Abstract: In this work we model the expected emission from the molecular line C17O(J=3-2) in protoplanetary disks, modifying different physical parameters to obtain distinctive observational signatures. Our aim is to determine the kind of observations that will allow us to extract information about the physical parameters of disks. With this purpose we perform a statistical analysis of principal components and a multiple linear correlation on our set of results from the models. We also present prospects for future molecular line observations of protoplanetary disks using SMA and ALMA., Comment: 11 pages, 3 figures. To appear in the "Revista Mexica de Astronomia y Astrofisica"
Published: 2007

4. A sensitive survey for water maser emission towards Bok globules using the Robledo 70m antenna

Author: Gomez, Jose F., de Gregorio-Monsalvo, Itziar, Suarez, Olga, and Kuiper, Thomas B. H.
Subjects: Astrophysics
Abstract: We report the most sensitive water maser survey towards Bok globules to date, using NASA's 70m antenna in Robledo de Chavela (Spain). We observed 207 positions within the CB catalog with a higher probability of harboring a young star, using as selection criteria the presence of radio continuum emission (from submillimeter to centimeter wavelengths), geometrical centers of molecular outflows, peaks in maps of high-density gas tracers (NH3 or CS), and IRAS point sources. We have obtained 7 maser detections, 6 of which (in CB 34, CB 54, CB 65, CB 101, CB 199, and CB 232) are reported for the first time here. Most of the water masers we detected are likely to be associated with young stellar objects (YSOs), except for CB 101 (probably an evolved object) and CB 65 (uncertain nature). The water maser in CB 199 shows a relatively high shift (~30 km/s) of its velocity centroid with respect to the cloud velocity, which is unusual for low-mass YSOs. We speculate that high-velocity masers in this kind of object could be related with episodes of energetic mass-loss in close binaries. Alternatively, the maser in CB 199 could be pumped by a protoplanetary or a young planetary nebula. CB 232 is the smallest Bok globule (~0.6 pc) known to be associated with water maser emission, although it would be superseded by the cases of CB 65 (~0.3 pc) and CB 199 (~0.5 pc) if their association with YSOs is confirmed. All our selection criteria have statistically compatible detection rates, except for IRAS sources, which tend to be a somewhat worse predictor for the presence of maser emission., Comment: 42 pages, 7 figures. Accepted by The Astronomical Journal. Corrected typos in Tables 1 & 3
Published: 2006
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5. A disk of dust and molecular gas around a high-mass protostar

Author: Patel, Nimesh A., Curiel, Salvador, Sridharan, T. K., Zhang, Qizhou, Hunter, Todd R., Ho, Paul T. P., Torrelles, Jose M., Moran, James M., Gomez, Jose F., and Anglada, Guillem
Subjects: Astrophysics
Abstract: The processes leading to the birth of low-mass stars such as our Sun have been well studied, but the formation of high-mass (> 8 x Sun's mass) stars has heretofore remained poorly understood. Recent observational studies suggest that high-mass stars may form in essentially the same way as low-mass stars, namely via an accretion process, instead of via merging of several low-mass (< 8 Msun) stars. However, there is as yet no conclusive evidence. Here, we report the discovery of a flattened disk-like structure observed at submillimeter wavelengths, centered on a massive 15 Msun protostar in the Cepheus-A region. The disk, with a radius of about 330 astronomical units (AU) and a mass of 1 to 8 Msun, is detected in dust continuum as well as in molecular line emission. Its perpendicular orientation to, and spatial coincidence with the central embedded powerful bipolar radio jet, provides the best evidence yet that massive stars form via disk accretion in direct analogy to the formation of low-mass stars.
Published: 2005
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6. Polarimetric Observations of 15 Active Galactic Nuclei at High Frequencies: Jet Kinematics from Bimonthly Monitoring with the Very Long Baseline Array

Author: Jorstad, Svetlana G., Marscher, Alan P., Lister, Matthew L., Stirling, Alastair M., Cawthorne, Timothy V., Gear, Walter K., Gomez, Jose L., Stevens, Jason A., Smith, Paul S., Forster, James R., and Robson, E. Ian
Subjects: Astrophysics
Abstract: We present total and polarized intensity images of 15 active galactic nuclei obtained with the Very Long Baseline Array at 7 mm at 17 epochs from 1998 March to 2001 April. At some epochs the images are accompanied by nearly simultaneous polarization measurements at 3 mm, 1.35/0.85 mm, and optical wavelengths. Here we analyze the 7 mm images to define the properties of the jets of two radio galaxies, five BL Lac objects, and eight quasars on angular scales $\gtrsim 0.1$ milliarcseconds. We determine the apparent velocities of 106 features in the jets; for many of the features we derive Doppler factors using a new method based on comparison of timescale of decline in flux density with the light-travel time across the emitting region. This allows us to estimate the Lorentz factors, intrinsic brightness temperatures, and viewing angles of 73 superluminal knots, as well as the opening angle of the jet for each source. We analyze the derived physical parameters of the jets. In nine sources we detect statistically meaningful deviations from ballistic motion, with the majority of components accelerating with distance from the core. In six sources we identify jet features with characteristics of trailing shocks that form behind the primary strong perturbations in jet simulations. The apparent speeds of these components increase with distance from the core suggesting an acceleration of the underlying jet., Comment: 100 pages, 44 figures, accepted for publication in AJ. This version does not contain figures 1-15,17(sequences of the images) due to very large size of the figures. The complete version (7mm_ms.ps) can be found at the website: www.bu.edu/blazars/multi.html
Published: 2005
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7. Molecular Line Emission from Accretion Disks Around YSOs

Author: de Gregorio-Monsalvo, Itziar, Gomez, Jose F., and D'Alessio, Paola
Subjects: Astrophysics
Abstract: In this work we model the expected molecular emission from protoplanetary disks, modifying different physical parameters, such as dust grain size, mass accretion rate, viscosity, and disk radius, to obtain observational signatures in these sources. Having in mind possible future observations, we study correlations between physical parameters and observational characteristics. Our aim is to determine the kind of observations that will allow us to extract information about the physical parameters of disks. We also present prospects for molecular line observations of protoplanetary disks, using millimeter and submillimeter interferometers (e.g., SMA or ALMA), based on our results., Comment: 6 pages, 2 figures. Proceeding of the workshop "Magnetic fields and star formation: theory versus observation", Madrid (Spain), April 21 - 25, 2003
Published: 2003
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8. A survey for water maser emission towards planetary nebulae. New detection in IRAS 17347-3139

Author: de Gregorio-Monsalvo, Itziar, Gomez, Yolanda, Anglada, Guillem, Cesaroni, Riccardo, Miranda, Luis F., Gomez, Jose F., and Torrelles, Jose M.
Subjects: Astrophysics
Abstract: We report on a water maser survey towards a sample of 27 planetary nebulae (PNe) using the Robledo de Chavela and Medicina single-dish antennas, as well as the Very Large Array (VLA). Two detections have been obtained: the already known water maser emission in K 3-35, and a new cluster of masers in IRAS 17347-3139. This low rate of detections is compatible with the short life-time of water molecules in PNe (~100 yr). The water maser cluster at IRAS 17347-3139 are distributed on a ellipse of size ~ 0.2" x 0.1", spatially associated with compact 1.3 cm continuum emission (simultaneously observed with the VLA). From archive VLA continuum data at 4.9, 8.4, and 14.9 GHz, a spectral index alpha = 0.76 +- 0.03 is derived for this radio source, which is consistent with either a partially optically thick ionized region or with an ionized wind. However, the latter scenario can be ruled out on mass-loss considerations, thus indicating that this source is probably a young PN. The spatial distribution and the radial velocities of the water masers are suggestive of a rotating and expanding maser ring, tracing the innermost regions of a torus formed at the end of the AGB phase. Given that the 1.3 cm continuum emission peak is located near one of the tips of the major axis of the ellipse of masers, we speculate on a possible binary nature of IRAS 17347-3139, where the radio continuum emission could belong to one of the components and the water masers would be associated with a companion., Comment: Accepted by The Astrophysical Journal. 25 pages, 6 figures
Published: 2003
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9. 3D Simulations of Relativistic Precessing Jets Probing the Structure of Superluminal Sources

Author: Aloy, Miguel Angel, Marti, Jose Maria, Gomez, Jose Luis, Agudo, Ivan, Mueller, Ewald, and Ibanyez, Jose Maria
Subjects: Astrophysics
Abstract: We present the results of a three-dimensional, relativistic, hydrodynamic simulation of a precessing jet into which a compact blob of matter is injected. A comparison of synthetic radio maps computed from the hydrodynamic model, taking into account the appropriate light travel time delays, with those obtained from observations of actual superluminal sources shows that the variability of the jet emission is the result of a complex combination of phase motions, viewing angle selection effects, and non-linear interactions between perturbations and the underlying jet and/or the external medium. These results question the hydrodynamic properties inferred from observed apparent motions and radio structures, and reveal that shock-in-jet models may be overly simplistic., Comment: Accepted for publication in ApJL. 4 pages, 5 figures (4 in color)
Published: 2003
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10. Monthly 43 GHz VLBA Polarimetric Monitoring of 3C120 over 16 Epochs: Evidence for Trailing Shocks in a Relativistic Jet

Author: Gomez, Jose-Luis, Marscher, Alan P., Alberdi, Antonio, Jorstad, Svetlana G., and Agudo, Ivan
Subjects: Astrophysics
Abstract: We present a 16-month sequence of monthly polarimetric 43 GHz VLBA images of the radio galaxy 3C 120. The images probe the inner regions of the radio jet of this relatively nearby superluminal radio galaxy at a linear resolution of 0.07 $h_{65}^{-1}$ pc ($H_o= 65 h_{65}$ km s$^{-1}$ Mpc$^{-1}$). We follow the motion of a number of features with apparent velocities between 4.01$\pm$0.08 and $5.82\pm 0.13 h_{65}^{-1} c$. A new superluminal knot, moving at $4.29\pm 0.16 h_{65}^{-1} c$, is observed to be ejected from the core at a time coincident with the largest flare ever observed for this source at millimeter wavelengths. Changes in the position angle of this component, as well as a progressive rotation of its magnetic polarization vector, suggest the presence of a twisted (resembling a helix in projection) configuration of the underlying jet magnetic field and jet geometry. We identify several knots that appear in the wake of the new superluminal component, moving at proper motions $\sim 4$ times slower than any of the other moving knots observed in 3C 120. These features have properties similar to those of the ``trailing'' shocks seen in relativistic, time-dependent, hydrodynamical and emission simulations of compact jets. Such trailing compressions are triggered by pinch-mode jet-body instabilities caused by the propagation of a strong perturbation, which we associate with the new strong superluminal component., Comment: 4 pages, 5 figures, accepted for publication in Astrophysical Journal Letters
Published: 2001
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11. Exact Solution for the Exterior Field of a Rotating Neutron Star

Author: Manko, Vladimir S., Mielke, Eckehard W., and Sanabria-Gómez, José D.
Subjects: General Relativity and Quantum Cosmology, Astrophysics
Abstract: A four-parameter class of exact asymptotically flat solutions of the Einstein-Maxwell equations involving only rational functions is presented. It is able to describe the exterior field of a slowly or rapidly rotating neutron star with poloidal magnetic field., Comment: Accepted for publication in Phys. Rev. D as Rapid Communication. 8 pages, 2 eps figures
Published: 2000
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12. Ammonia observations of the nearby molecular cloud MBM 12

Author: Gomez, Jose F., Trapero, Joaquin, Pascual, Sergio, Patel, Nimesh, Morales, Carmen, and Torrelles, Jose M.
Subjects: Astrophysics
Abstract: We present NH3(1,1) and NH3(2,2) observations of MBM 12, the closest known molecular cloud (65 pc distance), aimed to find evidence for on-going star formation processes. No local temperature (with a T_rot upper limit of 12 K) nor linewidth enhancement is found, which suggests that the area of the cloud we mapped (~ 15' size) is not currently forming stars. Therefore, this close ``starless'' molecular gas region is an ideal laboratory to study the physical conditions preceding new star formation. A radio continuum source was found in Very Large Array archive data, close but outside the NH3 emission. This source is likely to be a background object., Comment: 8 pages, 3 figures, accepted by MNRAS
Published: 2000
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13. Space VLBI Observations of 3C371

Author: Gomez, Jose-Luis and Marscher, Alan P.
Subjects: Astrophysics
Abstract: We present the first space VLBI observations of 3C~371, carried out at a frequency of 4.8 GHz. The combination of the high resolution provided by the orbiting antenna Highly Advanced Laboratory for Communications and Astronomy (HALCA) and the high sensitivity of the VLBA allows imaging of the jet of 3C~371 with an angular resolution of approximately 0.26 mas, which for this relatively nearby source corresponds to $\sim$ 0.4 h$^{-1}$ pc. Comparison between two epochs separated by 66 days reveals no apparent motions in the inner 7 mas jet structure above an upper limit of $\sim 1.4 h^{-1}$ c. This value, the absence of detectable counterjet emission from the presumably symmetric jet, plus the presence of extended double-lobe structure, are consistent with the knots in the jet being stationary features such as standing shocks. The jet intensity declines with the angular distance from the core as $\phi^{-1.68}$. This is more gradual than that derived for 3C~120, $\phi^{-1.86}$, for which there is evidence for strong intereactions between the jet and ambient medium. This suggests that in 3C~371 there is a greater level of {\it in situ} acceleration of electrons and amplification of magnetic field. We interpret sharp bends in the jet at sites of off-center knots as further evidence for the interaction between the jet and external medium, which may also be responsible for the generation of standing recollimation shocks. These recollimation shocks may be responsible for the presumably stationary components. The radio properties of 3C~371 are intermediate between those of other radio galaxies with bright cores and those of BL Lacertae objects., Comment: 5 pages, 4 figures. Accepted for publication in ApJ
Published: 1999
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14. Resolving Molecular Line Emission from Protoplanetary Disks: Observational Prospects for Disks Irradiated by Infalling Envelopes

Author: Gomez, Jose F. and D'Alessio, Paola
Subjects: Astrophysics
Abstract: Molecular line observations that could resolve protoplanetary disks of ~100 AU both spatially and kinematically would be a useful tool to unambiguously identify these disks and to determine their kinematical and physical characteristics. In this work we model the expected line emission from a protoplanetary disk irradiated by an infalling envelope, addressing the question of its detectability with subarcsecond resolution. We adopt a previously determined disk model structure that gives a continuum spectral energy distribution and a mm intensity spatial distribution that are consistent with observational constraints of HL Tau. An analysis of the capability of presently working and projected interferometers at mm and submm wavelengths shows that molecular transitions of moderate opacity at these wavelengths (e.g., C17O lines) are good candidates for detecting disk lines at subarcsecond resolution in the near future. We suggest that, in general, disks of typical Class I sources will be detectable., Comment: 41 pages, 16 figures. To be published in The Astrophysical Journal
Published: 1999
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15. Radio Emission from 3D Relativistic Hydrodynamic Jets: Observational Evidence of Jet Stratification

Author: Aloy, Miguel-Angel, Gomez, Jose-Luis, Ibanez, Jose-Maria, Marti, Jose-Maria, and Mueller, Ewald
Subjects: Astrophysics
Abstract: We present the first radio emission simulations from high resolution three dimensional relativistic hydrodynamic jets, which allow for a study of the observational implications of the interaction between the jet and external medium. This interaction gives rise to a stratification of the jet where a fast spine is surrounded by a slow high energy shear layer. The stratification, and in particular the large specific internal energy and slow flow in the shear layer largely determines the emission from the jet. If the magnetic field in the shear layer becomes helical (e.g., resulting from an initial toroidal field and an aligned field component generated by shear) the emission shows a cross section asymmetry, in which either the top or the bottom of the jet dominates the emission. This, as well as limb or spine brightening, is a function of the viewing angle and flow velocity, and the top/bottom jet emission predominance can be reversed if the jet changes direction with respect to the observer, or presents a change in velocity. The asymmetry is more prominent in the polarized flux, because of field cancellation (or amplification) along the line of sight. Recent observations of jet cross section emission asymmetries in the blazar 1055+018 can be explained assuming the existence of a shear layer with a helical magnetic field., Comment: 6 pages, 5 figures, 1 latex style file, ApJL accepted
Published: 1999
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16. Simulations of Relativistic Jets with GENESIS

Author: Aloy, Miguel A., Ibanez, Jose M., Marti, Jose M., Gomez, Jose L., and Mueller, Ewald
Subjects: Astrophysics
Abstract: The multidimensional relativistic hydrodynamical code GENESIS has been used to obtain first results of {\it 3D} simulations of relativistic jets. We have studied the influence of a slight perturbation of the injection velocity field on the morphodynamics of otherwise axisymmetric relativistic jets., Comment: 6 pages, 2 figures, to appear in the proceedings of the conference "Godunov methods: theory and applications", Oxford, October 1999
Published: 1999

17. Far Ultraviolet Absolute Flux of alpha Virginis

Author: Morales, Carmen, Trapero, Joaquin, Gomez, Jose F., Gimenez, Alvaro, Orozco, Veronica, Bowyer, Stuart, Edelstein, Jerry, Korpela, Eric, Lampton, Michael, and Cobb, Jeff
Subjects: Astrophysics
Abstract: We present the far ultraviolet spectrum of alpha Virginis taken with EURD spectrograph on-board MINISAT-01. The spectral range covered is from ~900 to 1080 A with 5 A spectral resolution. We have fitted Kurucz models to IUE spectra of alpha Vir and compared the extension of the model to our wavelengths with EURD data. This comparison shows that EURD fluxes are consistent with the prediction of the model within 20-30%, depending on the reddening assumed. EURD fluxes are consistent with Voyager observations but are ~60% higher than most previous rocket observations of alpha Vir., Comment: 13 pages, 4 figures. Submitted to The Astrophysical Journal
Published: 1999
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18. Evidence Against the Sciama Model of Radiative Decay of Massive Neutrinos

Author: Bowyer, Stuart, Korpela, Eric J., Edelstein, Jerry, Lampton, Michael, Morales, Carmen, Perez-Mercader, Juan, Gomez, Jose F., and Trapero, Joaquin
Subjects: Astrophysics
Abstract: We report on spectral observations of the night sky in the band around 900 angstroms where the emission line in the Sciama model of radiatively decaying massive neutrinos would be present. The data were obtained with a high resolution, high sensitivity spectrometer flown on the Spanish MINISAT satellite. The observed emission is far less intense than that expected in the Sciama model., Comment: 9 pages, accepted to ApJ
Published: 1999
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19. 86, 43, and 22 GHz VLBI Observations of 3C120

Author: Gomez, Jose-Luis, Marscher, Alan P., and Alberdi, Antonio
Subjects: Astrophysics
Abstract: We present the first 86 GHz VLBI observations of the radio galaxy 3C~120, together with contemporaneous 43 and 22 GHz polarimetric VLBA observations. The very high angular resolution obtained at 86 GHz provides an upper limit to the size of the core of 54 $\mu$as (0.025 $h^{-1}$pc). This represents a direct determination of the base of the jet which is independent of variability arguments (which depend on uncertain estimates of the Doppler factor), and places it below approximately one light-month. Comparison with previous VLBA observations after a one-year interval shows pronounced changes in the structure and polarization of the jet. Most of the components are found to follow a curved path while undergoing a steepening of their spectra accompanied by a decrease in total and polarized emission. However, at least one component is observed to follow a quasi-ballistic motion, accompanied by a flattening of its spectrum, as well as an increase in total and polarized flux. This may be explained by its interaction with the external medium, resulting in a shock that enhances the emission and aligns the magnetic field perpendicular to the component motion, thereby producing an increase of the degree of polarization from undetected values to as high as 15%. A second strong component, with the highest degree of polarization (23%), is found to have experienced a displacement from the ridge line of the structural position angle of the jet as it moved downstream. We have found a mean swing to the south of the position angle of the innermost components of $\sim 6^{\circ}$ between late 1996 and 1997, which may be responsible for the jet curvature observed at parsec and kiloparsec scales., Comment: 12 pages, 1 figure. Accepted for publication in ApJ Letters
Published: 1999
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20. Outburst in the Polarized Structure of the Compact Jet of 3C454.3

Author: Gomez, Jose-Luis, Marscher, Alan P., and Alberdi, Antonio
Subjects: Astrophysics
Abstract: We present three-epoch polarimetric images of the quasar 3C 454.3 obtained with the Very Long Baseline Array at 22 and 43 GHz. 22 GHz polarized intensity images show a sudden change in the polarization structure of a bright eastern component (which we call the ``core,'' although it may be neither at the upstream end of the jet nor completely stationary) over a 41-day interval, coincident with the ejection of a new component from the core, as resolved in the corresponding 43 GHz images. This polarization outburst is also present at 43 GHz in both the core and the new component. This may represent a rapid change in the electric vector position angle of the ejected component from being orthogonal to almost parallel to that of the core. About seven months later, the new component, moving superluminally at 2.9 \pm 0.4 h^{-1} c$ (q_{\circ}=0.5) relative to the core and 3.9 \pm 0.4 h^{-1} c$ relative to a bright stationary component about 0.6 mas west of the core --- very low compared with previous measurements --- is found at 43 GHz to exhibit a further rotation of 90$^{\circ}$ in the orientation of its polarization. Opacity effects may account for the first rotation, but changes in the magnetic field of the component and/or that of the underlying jet in the inner milliarcsecond structure of 3C 454.3 are needed to account for the second. Polarized intensity images of the quasar 0420 - 014, used as a calibrator, are also presented. The polarization position angle of the core rotated between late 1994 and late 1996., Comment: 21 pages, 3 figures. Accepted in ApJ
Published: 1999
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21. The twisted parsec-scale structure of 0735+178

Author: Gomez, Jose-Luis, Marscher, Alan P., Alberdi, Antonio, and Gabuzda, Denise C.
Subjects: Astrophysics
Abstract: We present two epoch polarimetric images of the BL Lac object 0735+178 obtained with the Very Long Baseline Array at 22 and 43 GHz. These images provide the highest resolution observations of this source to date, and show a twisted jet with two sharp apparent bends of 90 deg. within two milliarcseconds of the core. The magnetic field appears to smoothly follow one of the bends in the jet, suggesting that this structure may be the result of a precessing nozzle in the jet of 0735+178. Proper motion information is not conclusive as to whether the twisted geometry is the result of knots moving ballistically or following the direction of the jet axis., Comment: 6 pages, accepted for publication in ApJ
Published: 1999
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22. Indication of a mass-dependent anisotropy above 10 18.7 eV in the hybrid data of the Pierre Auger Observatory

Author: Pierre Auger Collaboration, Mayotte, Eric, Abreu, Pedro, Aglietta, Marco, Albury, Justin M., Allekotte, Ingomar, Almela, Alejandro, Alvarez-Muniz, Jaime, Alves Batista, Rafael, Anastasi, Gioacchino Alex, Anchordoqui, Luis A., Andrada, Belén, Andringa, Sofia, Aramo, Carla, Araújo Ferreira, Paulo Ricardo, Arteaga Velazquez, Juan Carlos, Asorey, Hernán Gonzalo, Assis, Pedro, Avila, Gualberto, Badescu, Alina Mihaela, Bakalova, Alena, Balaceanu, Alexandru, Barbato, Felicia, Barreira Luz, Ricardo Jorge, Becker, Karl-Heinz, Bellido, Jose A., Berat, Corinne, Bertaina, Mario Edoardo, Bertou, Xavier, Biermann, Peter L., Binet, Virginia, Bismark, Kathrin, Bister, Teresa, Biteau, Jonathan, Blazek, Jiri, Bleve, Carla, Bohacova, Martina, boncioli, denise, Bonifazi, Carla, Bonneau Arbeletche, Luan, Borodai, Nataliia, Botti, Ana Martina, Brack, Jeffrey, Bretz, Thomas, Brichetto Orchera, P. Gabriel, Briechle, Florian Lukas, Buchholz, Peter, Bueno, Antonio, Buitink, Stijn, Buscemi, Mario, Büsken, Max, Caballero-Mora, Karen S., Caccianiga, Lorenzo, Canfora, Fabrizia, Caracas, Ioana, Carceller, Juan Miguel, Caruso, Rossella, Castellina, Antonella, Catalani, Fernando, Cataldi, Gabriella, Cazon, Lorenzo, Cerda, Marcos, Chinellato, Jose Augusto, Chudoba, Jiri, Chytka, Ladislav, Clay, Roger W., Cobos Cerutti, Agustín, Colalillo, Roberta, Coleman, Alan, Coluccia, Maria Rita, Conceição, Rúben, Condorelli, Antonio, Consolati, Giovanni, Contreras, Fernando, Convenga, Fabio, Correia dos Santos, Diego, Covault, Corbin, Dasso, Sergio, Daumiller, Kai, Dawson, Bruce R., Day, Jarryd A., Almeida, Rogerio M. de, Jesús, Joaquín de, Jong, Sijbrand J. de, De Mauro, Giuseppe, Mello Neto, João de, De Mitri, Ivan, Oliveira, Jaime de, Oliveira Franco, Danelise de, Palma, Francesco de, Souza, Vitor de, De Vito, Emanuele, Río, Mariano del, Deligny, Olivier, Deval, Luca, Matteo, Armando di, Dobrigkeit, Carola, D'Olivo, Juan Carlos, Domingues Mendes, Luis Miguel, Anjos, Rita dos, Santos, Diego dos, Dova, Maria Teresa, Ebr, Jan, Engel, Ralph, Epicoco, Italo, Erdmann, Martin, Escobar, Carlos O., Etchegoyen, Alberto, Falcke, Heino, Farmer, John, Farrar, Glennys R., Fauth, Anderson, Fazzini, Norberto, Feldbusch, Fridtjof, Fenu, Francesco, Fick, Brian, Figueira, Juan Manuel, Filipcic, Andrej, Fitoussi, Thomas, Fodran, Tomáš, Freire, Martín Miguel, Fujii, Toshihiro, Fuster, Alan, Galea, Cristina, Galelli, Claudio, García, Beatriz, García Vegas, Adrianna Luz, Gemmeke, Hartmut, Gesualdi, Flavia, Gherghel-Lascu, Alexandru, Ghia, Piera Luisa, GIACCARI, Ugo, Giammarchi, Marco, Glombitza, Jonas, Gobbi, Fabian, Gollan, Fernando, Golup, Geraldina, Gómez Berisso, Mariano, Gómez Vitale, Primo F., Gongora, Juan Pablo, González, Juan Manuel, Gonzalez, Nicolas Martin, Goos, Isabel, Gora, Dariusz, Gorgi, Alessio, Gottowik, Marvin, Grubb, Trent D., Guarino, Fausto, Guedes, Germano, Guido, Eleonora, Hahn, Steffen, Hamal, Petr, Hampel, Matías Rolf, Hansen, Patricia María, Harari, Diego, Harvey, Violet M., Haungs, Andreas, Hebbeker, Thomas, Heck, Dieter, Hill, Gary C., Hojvat, Carlos, Hörandel, Jörg, Horvath, Pavel, Hrabovsky, Miroslav, Huege, Tim, Insolia, Antonio, Isar, Paula Gina, Janecek, Petr, Johnsen, Jeffrey A., Juryšek, Jakub, Kääpä, Alex, Kampert, Karl-Heinz, Karastathis, Nikolaos, Keilhauer, Bianca, Kemp, Julian, Khakurdikar, Abha, Kizakke Covilakam, Varada Varma, Klages, Hans, Kleifges, Matthias, Kleinfeller, Jonny, Köpke, Marcel, Kunka, Norbert, Lago, Bruno L., Lang, Rodrigo Guedes, Langner, Niklas, Leigui de Oliveira, Marcelo Augusto, Lenok, Vladimir, Letessier-Selvon, Antoine, Lhenry-Yvon, Isabelle, Lo Presti, Domenico, LOPES, Luis, López, Rebeca, Lu, Lu, Luce, Quentin, Lundquist, Jon Paul, Machado Payeras, Allan, Mancarella, Giovanni, Mandat, Dusan, Manning, Bradley C., Manshanden, Julien, Mantsch, Paul, Marafico, Sullivan, Mariazzi, Analisa, Maris, Ioana Codrina, Marsella, Giovanni, Martello, Daniele, Martinelli, Sara, Martínez Bravo, Oscar, Mastrodicasa, Massimo, Mathes, Hermann-Josef, Matthews, James, Matthiae, Giorgio, Mazur, Peter, Medina-Tanco, Gustavo, Melo, Diego, Menshikov, Alexander, Merenda, Kevin-Druis, Michal, Stanislav, Micheletti, Maria Isabel, Miramonti, Lino, Mollerach, Silvia, Montanet, François, Morello, Carlo, Mostafa, Miguel, Müller, Ana L., Muller, Marcio Aparecido, Mulrey, Katharine, Mussa, Roberto, Muzio, Marco Stein, Namasaka, Wilson M., Nasr-Esfahani, Alina, Nellen, Lukas, Niculescu-Oglinzanu, Mihai, Niechciol, Marcus, Nitz, Dave, Nosek, Dalibor, Novotný, Vladimír, Nozka, Libor, Nucita, Achille, Nunez, Luis A., Palatka, Miroslav, Pallotta, Juan, Papenbreer, Philipp, Parente, Gonzalo, Parra, Alejandra, Pawlowsky, Jannis, Pech, Miroslav, Pedreira, Francisco, Pękala, Jan, Pelayo, Rodrigo, Peña-Rodríguez, Jesús, Pereira Martins, Edyvania Emily, Perez Armand, Johnnier, Pérez Bertolli, Carmina, Perlin, Matías, Perrone, Lorenzo, Petrera, Sergio, Pierog, Tanguy, Pimenta, Mário, Pirronello, Valerio, Platino, Manuel, Pont, Bjarni, Pothast, Mart, Privitera, Paolo, Prouza, Michael, Puyleart, Andrew, Querchfeld, Sven, Rautenberg, Julian, Ravignani, Diego, Reininghaus, Maximilian, Ridky, Jan, Riehn, Felix, Risse, Markus, Rizi, Vincenzo, Rodrigues de Carvalho, Washington, Rodriguez Rojo, Jorge Rubén, Roncoroni, Matías J., Rossoni, Simone, Roth, Markus, Roulet, Esteban, Rovero, Adrian, Ruehl, Philip, Saftoiu, Alexandra, Salamida, Francesco, Salazar, Humberto Ibarguen, Salina, Gaetano, Sanabria Gomez, Jose, Sánchez, Federico Andrés, Santos, Edivaldo Moura, Santos, Eva, Sarazin, Fred, Sarmento, Raul, Sarmiento-Cano, Christian, Sato, Ricardo, Savina, Pierpaolo, Schäfer, Christoph M., Scherini, Viviana, Schieler, Harald, Schimassek, Martin, Schimp, Michael, Schlüter, Felix, Schmidt, David, Scholten, Olaf, Schovanek, Petr, Schröder, Frank G., Schröder, Sonja, Schulte, Josina, Sciutto, Sergio, Scornavacche, Marina, Segreto, Alberto, Sehgal, Srijan, Shellard, Ronald C., Sigl, Guenter, Silli, Gaia, Sima, Octavian, Smida, Radomir, Sommers, Paul, Soriano, Jorge F., Souchard, Julien, Squartini, Ruben, Stadelmaier, Maximilian, Stanca, Denis, Stanič, Samo, Stasielak, Jaroslaw, Stassi, Patrick, Streich, Alexander, Suárez-Durán, Mauricio, Sudholz, Tristan, Suomijarvi, Tiina, Supanitsky, A. Daniel, Szadkowski, Zbigniew, Tapia, Alex, Taricco, Carla, Timmermans, Charles, Tkachenko, Olena, Tobiska, Petr, Todero Peixoto, Carlos J., Tomé, Bernardo, Torrès, Zoé, Travaini, Andres, Travnicek, Petr, Trimarelli, Caterina, Tueros, Matias, Ulrich, Ralf, Unger, Michael, Vaclavek, Lukáš, Vacula, Martin, Valdés Galicia, Jose F., Valore, Laura, Varela, Enrique, Vásquez-Ramírez, Adriana, Veberic, Darko, Ventura, Cynthia, Vergara Quispe, Indira D., Verzi, Valerio, Vicha, Jakub, Vink, Jacco, Vorobiov, Serguei, Wahlberg, Hernan, Watanabe, Clara Keiko Oliveira, Watson, Alan, Weber, Marc, Weindl, Andreas, Wiencke, Lawrence, Wilczyński, Henryk, Wirtz, Marcus, Wittkowski, David, Wundheiler, Brian, Yushkov, Alexey, Zapparrata, Orazio, Zas, Enrique, Zavrtanik, Danilo, Zavrtanik, Marko, and Zehrer, Lukas
Subjects: Physics, Pierre Auger Observatory, Astronomy, Astrophysics, Galactic plane, Mass composition, Threshold energy, Distribution (mathematics), Experimental High Energy Physics, Sensitivity (control systems), High Energy Physics, ddc:620, Anisotropy, Hybrid data, Engineering & allied operations
Abstract: We test the hypothesis of an anisotropy laying along the galactic plane which depends on the mass of primary cosmic-rays. The sensitivity to primary mass is provided by the depth of shower maximum, $X_\text{max}$, from hybrid events measured at the Pierre Auger Observatory. The 14 years of available data are split into on- and off-plane regions using the galactic latitude of each event to form two distributions in $X_\text{max}$, which are compared using the Anderson-Darling 2-samples test. A scan over a subset of the data is used to select an optimal threshold energy of $10^{18.7}$ eV and a galactic latitude splitting at $|b| = 30^\circ$, which are then set as a prescription for the remaining data. With these thresholds, the distribution of $X_\text{max}$ from the on-plane region is found to have a $9.1 \pm 1.6^{+2.1}_{-2.2}$ g/cm$^{2}$ shallower mean and a $5.9\pm2.1^{+3.5}_{-2.5}$ g/cm$^{2}$ narrower width than that of the off-plane region. These differences are as such to indicate that the mean mass of primary particles arriving from the on-plane region is greater than that of those coming from the off-plane region. Monte-Carlo studies yield a $4.4\,\sigma$ post-penalization statistical significance for the independent data. Including the scanned data results in a $4.9^{+1.4}_{-1.5}\,\sigma$ post-penalization statistical significance, where the uncertainties are of systematic origin. Accounting for systematic uncertainties leads to an indication for anisotropy in mass composition above $10^{18.7}$ eV at a confidence level of $3.3\,\sigma$. The anisotropy is observed independently at each of the four fluorescence telescope sites. Interpretations of possible causes of the observed effect are discussed.
Published: 2022

23. A tau scenario application to a search for upward-going showers with the Fluorescence Detector of the Pierre Auger Observatory

Author: Pierre Auger Collaboration, Caracas, Ioana Alexandra, Abreu, Pedro, Aglietta, Marco, Albury, Justin M., Allekotte, Ingomar, Almela, Alejandro, Alvarez-Muniz, Jaime, Alves Batista, Rafael, Anastasi, Gioacchino Alex, Anchordoqui, Luis A., Andrada, Belén, Andringa, Sofia, Aramo, Carla, Araújo Ferreira, Paulo Ricardo, Arteaga Velazquez, Juan Carlos, Asorey, Hernán Gonzalo, Assis, Pedro, Avila, Gualberto, Badescu, Alina Mihaela, Bakalova, Alena, Balaceanu, Alexandru, Barbato, Felicia, Barreira Luz, Ricardo Jorge, Becker, Karl-Heinz, Bellido, Jose A., Berat, Corinne, Bertaina, Mario Edoardo, Bertou, Xavier, Biermann, Peter L., Binet, Virginia, Bismark, Kathrin, Bister, Teresa, Biteau, Jonathan, Blazek, Jiri, Bleve, Carla, Bohacova, Martina, boncioli, denise, Bonifazi, Carla, Bonneau Arbeletche, Luan, Borodai, Nataliia, Botti, Ana Martina, Brack, Jeffrey, Bretz, Thomas, Brichetto Orchera, P. Gabriel, Briechle, Florian Lukas, Buchholz, Peter, Bueno, Antonio, Buitink, Stijn, Buscemi, Mario, Büsken, Max, Caballero-Mora, Karen S., Caccianiga, Lorenzo, Canfora, Fabrizia, Caracas, Ioana, Carceller, Juan Miguel, Caruso, Rossella, Castellina, Antonella, Catalani, Fernando, Cataldi, Gabriella, Cazon, Lorenzo, Cerda, Marcos, Chinellato, Jose Augusto, Chudoba, Jiri, Chytka, Ladislav, Clay, Roger W., Cobos Cerutti, Agustín, Colalillo, Roberta, Coleman, Alan, Coluccia, Maria Rita, Conceição, Rúben, Condorelli, Antonio, Consolati, Giovanni, Contreras, Fernando, Convenga, Fabio, Correia dos Santos, Diego, Covault, Corbin, Dasso, Sergio, Daumiller, Kai, Dawson, Bruce R., Day, Jarryd A., Almeida, Rogerio M. de, Jesús, Joaquín de, Jong, Sijbrand J. de, De Mauro, Giuseppe, Mello Neto, João de, De Mitri, Ivan, Oliveira, Jaime de, Oliveira Franco, Danelise de, Palma, Francesco de, Souza, Vitor de, De Vito, Emanuele, Río, Mariano del, Deligny, Olivier, Deval, Luca, Matteo, Armando di, Dobrigkeit, Carola, D'Olivo, Juan Carlos, Domingues Mendes, Luis Miguel, Anjos, Rita dos, Santos, Diego dos, Dova, Maria Teresa, Ebr, Jan, Engel, Ralph, Epicoco, Italo, Erdmann, Martin, Escobar, Carlos O., Etchegoyen, Alberto, Falcke, Heino, Farmer, John, Farrar, Glennys R., Fauth, Anderson, Fazzini, Norberto, Feldbusch, Fridtjof, Fenu, Francesco, Fick, Brian, Figueira, Juan Manuel, Filipcic, Andrej, Fitoussi, Thomas, Fodran, Tomáš, Freire, Martín Miguel, Fujii, Toshihiro, Fuster, Alan, Galea, Cristina, Galelli, Claudio, García, Beatriz, García Vegas, Adrianna Luz, Gemmeke, Hartmut, Gesualdi, Flavia, Gherghel-Lascu, Alexandru, Ghia, Piera Luisa, GIACCARI, Ugo, Giammarchi, Marco, Glombitza, Jonas, Gobbi, Fabian, Gollan, Fernando, Golup, Geraldina, Gómez Berisso, Mariano, Gómez Vitale, Primo F., Gongora, Juan Pablo, González, Juan Manuel, Gonzalez, Nicolas Martin, Goos, Isabel, Gora, Dariusz, Gorgi, Alessio, Gottowik, Marvin, Grubb, Trent D., Guarino, Fausto, Guedes, Germano, Guido, Eleonora, Hahn, Steffen, Hamal, Petr, Hampel, Matías Rolf, Hansen, Patricia María, Harari, Diego, Harvey, Violet M., Haungs, Andreas, Hebbeker, Thomas, Heck, Dieter, Hill, Gary C., Hojvat, Carlos, Hörandel, Jörg, Horvath, Pavel, Hrabovsky, Miroslav, Huege, Tim, Insolia, Antonio, Isar, Paula Gina, Janecek, Petr, Johnsen, Jeffrey A., Juryšek, Jakub, Kääpä, Alex, Kampert, Karl-Heinz, Karastathis, Nikolaos, Keilhauer, Bianca, Kemp, Julian, Khakurdikar, Abha, Kizakke Covilakam, Varada Varma, Klages, Hans, Kleifges, Matthias, Kleinfeller, Jonny, Köpke, Marcel, Kunka, Norbert, Lago, Bruno L., Lang, Rodrigo Guedes, Langner, Niklas, Leigui de Oliveira, Marcelo Augusto, Lenok, Vladimir, Letessier-Selvon, Antoine, Lhenry-Yvon, Isabelle, Lo Presti, Domenico, LOPES, Luis, López, Rebeca, Lu, Lu, Luce, Quentin, Lundquist, Jon Paul, Machado Payeras, Allan, Mancarella, Giovanni, Mandat, Dusan, Manning, Bradley C., Manshanden, Julien, Mantsch, Paul, Marafico, Sullivan, Mariazzi, Analisa, Maris, Ioana Codrina, Marsella, Giovanni, Martello, Daniele, Martinelli, Sara, Martínez Bravo, Oscar, Mastrodicasa, Massimo, Mathes, Hermann-Josef, Matthews, James, Matthiae, Giorgio, Mayotte, Eric, Mazur, Peter, Medina-Tanco, Gustavo, Melo, Diego, Menshikov, Alexander, Merenda, Kevin-Druis, Michal, Stanislav, Micheletti, Maria Isabel, Miramonti, Lino, Mollerach, Silvia, Montanet, François, Morello, Carlo, Mostafa, Miguel, Müller, Ana L., Muller, Marcio Aparecido, Mulrey, Katharine, Mussa, Roberto, Muzio, Marco Stein, Namasaka, Wilson M., Nasr-Esfahani, Alina, Nellen, Lukas, Niculescu-Oglinzanu, Mihai, Niechciol, Marcus, Nitz, Dave, Nosek, Dalibor, Novotný, Vladimír, Nozka, Libor, Nucita, Achille, Nunez, Luis A., Palatka, Miroslav, Pallotta, Juan, Papenbreer, Philipp, Parente, Gonzalo, Parra, Alejandra, Pawlowsky, Jannis, Pech, Miroslav, Pedreira, Francisco, Pękala, Jan, Pelayo, Rodrigo, Peña-Rodríguez, Jesús, Pereira Martins, Edyvania Emily, Perez Armand, Johnnier, Pérez Bertolli, Carmina, Perlin, Matías, Perrone, Lorenzo, Petrera, Sergio, Pierog, Tanguy, Pimenta, Mário, Pirronello, Valerio, Platino, Manuel, Pont, Bjarni, Pothast, Mart, Privitera, Paolo, Prouza, Michael, Puyleart, Andrew, Querchfeld, Sven, Rautenberg, Julian, Ravignani, Diego, Reininghaus, Maximilian, Ridky, Jan, Riehn, Felix, Risse, Markus, Rizi, Vincenzo, Rodrigues de Carvalho, Washington, Rodriguez Rojo, Jorge Rubén, Roncoroni, Matías J., Rossoni, Simone, Roth, Markus, Roulet, Esteban, Rovero, Adrian, Ruehl, Philip, Saftoiu, Alexandra, Salamida, Francesco, Salazar, Humberto Ibarguen, Salina, Gaetano, Sanabria Gomez, Jose, Sánchez, Federico Andrés, Santos, Edivaldo Moura, Santos, Eva, Sarazin, Fred, Sarmento, Raul, Sarmiento-Cano, Christian, Sato, Ricardo, Savina, Pierpaolo, Schäfer, Christoph M., Scherini, Viviana, Schieler, Harald, Schimassek, Martin, Schimp, Michael, Schlüter, Felix, Schmidt, David, Scholten, Olaf, Schovanek, Petr, Schröder, Frank G., Schröder, Sonja, Schulte, Josina, Sciutto, Sergio, Scornavacche, Marina, Segreto, Alberto, Sehgal, Srijan, Shellard, Ronald C., Sigl, Guenter, Silli, Gaia, Sima, Octavian, Smida, Radomir, Sommers, Paul, Soriano, Jorge F., Souchard, Julien, Squartini, Ruben, Stadelmaier, Maximilian, Stanca, Denis, Stanič, Samo, Stasielak, Jaroslaw, Stassi, Patrick, Streich, Alexander, Suárez-Durán, Mauricio, Sudholz, Tristan, Suomijarvi, Tiina, Supanitsky, A. Daniel, Szadkowski, Zbigniew, Tapia, Alex, Taricco, Carla, Timmermans, Charles, Tkachenko, Olena, Tobiska, Petr, Todero Peixoto, Carlos J., Tomé, Bernardo, Torrès, Zoé, Travaini, Andres, Travnicek, Petr, Trimarelli, Caterina, Tueros, Matias, Ulrich, Ralf, Unger, Michael, Vaclavek, Lukáš, Vacula, Martin, Valdés Galicia, Jose F., Valore, Laura, Varela, Enrique, Vásquez-Ramírez, Adriana, Veberic, Darko, Ventura, Cynthia, Vergara Quispe, Indira D., Verzi, Valerio, Vicha, Jakub, Vink, Jacco, Vorobiov, Serguei, Wahlberg, Hernan, Watanabe, Clara Keiko Oliveira, Watson, Alan, Weber, Marc, Weindl, Andreas, Wiencke, Lawrence, Wilczyński, Henryk, Wirtz, Marcus, Wittkowski, David, Wundheiler, Brian, Yushkov, Alexey, Zapparrata, Orazio, Zas, Enrique, Zavrtanik, Danilo, Zavrtanik, Marko, and Zehrer, Lukas
Subjects: Pierre Auger Observatory, Physics, Astronomy, Astrophysics::High Energy Astrophysical Phenomena, Detector, Astrophysics::Instrumentation and Methods for Astrophysics, Flux, Astrophysics, Spectral line, Path length, Experimental High Energy Physics, High Energy Physics::Experiment, High Energy Physics, ddc:620, Engineering & allied operations, Energy (signal processing), Intensity (heat transfer), Zenith
Abstract: Recent observations of two coherent radio pulses with the ANITA detector can be interpreted as steeply upward-going cosmic-ray showers with energies of a few tenths of an EeV and remain unexplained. The Pierre Auger Observatory has a large exposure to such upward propagating shower-like events, and has used 14 years of its Fluorescence Detector (FD) data to perform a generic search for such events with elevation angles greater than 20$^\circ$ from the horizon. Here this search is recast to constrain models generating high energy $\tau$-leptons. For maximal flexibility, only the propagation, decay, and interactions of $\tau$-leptons are treated in this analysis, meaning that the results are independent of the $\tau$-production scenario. This treatment allows for the application of these results to the wide range of models producing $\tau$-leptons that have been proposed to describe the "anomalous" ANITA events. The goal of this study is accomplished by generating $\tau$-leptons within the Earth and its atmosphere with an intensity dependent on the media density. The zenith angle, location and calorimetric energy of any resulting $\tau$-induced air showers are then used to calculate the exposure of the FD of the Pierre Auger Observatory to $\tau$ primaries. Differential limits as low as $10^{-9}$GeV s$^{-1}$cm$^{-2}$sr$^{-1}$ to the flux of $\tau$-leptons produced with less than a 50 km path length below the Earth's surface are reported for several zenith angle ranges and primary energy spectra. Full exposure and sensitivity information is provided, facilitating the application of these results to different $\tau$-lepton production models.
Published: 2022

24. Study on multi-ELVES in the Pierre Auger Observatory

Author: Collaboration, Pierre Auger, V��squez Ram��rez, Adriana, Abreu, Pedro, Aglietta, Marco, Albury, Justin M., Allekotte, Ingomar, Almela, Alejandro, Alvarez-Muniz, Jaime, Alves Batista, Rafael, Anastasi, Gioacchino Alex, Anchordoqui, Luis A., Andrada, Bel��n, Andringa, Sofia, Aramo, Carla, Ara��jo Ferreira, Paulo Ricardo, Arteaga Velazquez, Juan Carlos, Asorey, Hern��n Gonzalo, Assis, Pedro, Avila, Gualberto, Badescu, Alina Mihaela, Bakalova, Alena, Balaceanu, Alexandru, Barbato, Felicia, Barreira Luz, Ricardo Jorge, Becker, Karl-Heinz, Bellido, Jose A., Berat, Corinne, Bertaina, Mario Edoardo, Bertou, Xavier, Biermann, Peter L., Binet, Virginia, Bismark, Kathrin, Bister, Teresa, Biteau, Jonathan, Blazek, Jiri, Bleve, Carla, Bohacova, Martina, Boncioli, Denise, Bonifazi, Carla, Bonneau Arbeletche, Luan, Borodai, Nataliia, Botti, Ana Martina, Brack, Jeffrey, Bretz, Thomas, Brichetto Orchera, P. Gabriel, Briechle, Florian Lukas, Buchholz, Peter, Bueno, Antonio, Buitink, Stijn, Buscemi, Mario, B��sken, Max, Caballero-Mora, Karen S., Caccianiga, Lorenzo, Canfora, Fabrizia, Caracas, Ioana, Carceller, Juan Miguel, Caruso, Rossella, Castellina, Antonella, Catalani, Fernando, Cataldi, Gabriella, Cazon, Lorenzo, Cerda, Marcos, Chinellato, Jose Augusto, Chudoba, Jiri, Chytka, Ladislav, Clay, Roger W., Cobos Cerutti, Agust��n, Colalillo, Roberta, Coleman, Alan, Coluccia, Maria Rita, Concei��o, R��ben, Condorelli, Antonio, Consolati, Giovanni, Contreras, Fernando, Convenga, Fabio, Correia Dos Santos, Diego, Covault, Corbin, Dasso, Sergio, Daumiller, Kai, Dawson, Bruce R., Day, Jarryd A., Almeida, Rogerio M. De, Jes��s, Joaqu��n De, Jong, Sijbrand J. De, De Mauro, Giuseppe, Mello Neto, Jo��o De, De Mitri, Ivan, Oliveira, Jaime De, Oliveira Franco, Danelise De, Palma, Francesco De, Souza, Vitor De, De Vito, Emanuele, R��o, Mariano Del, Deligny, Olivier, Deval, Luca, Matteo, Armando Di, Dobrigkeit, Carola, D'Olivo, Juan Carlos, Domingues Mendes, Luis Miguel, Anjos, Rita Dos, Santos, Diego Dos, Dova, Maria Teresa, Ebr, Jan, Engel, Ralph, Epicoco, Italo, Erdmann, Martin, Escobar, Carlos O., Etchegoyen, Alberto, Falcke, Heino, Farmer, John, Farrar, Glennys R., Fauth, Anderson, Fazzini, Norberto, Feldbusch, Fridtjof, Fenu, Francesco, Fick, Brian, Figueira, Juan Manuel, Filipcic, Andrej, Fitoussi, Thomas, Fodran, Tom��, Freire, Mart��n Miguel, Fujii, Toshihiro, Fuster, Alan, Galea, Cristina, Galelli, Claudio, Garc��a, Beatriz, Garc��a Vegas, Adrianna Luz, Gemmeke, Hartmut, Gesualdi, Flavia, Gherghel-Lascu, Alexandru, Ghia, Piera Luisa, GIACCARI, Ugo, Giammarchi, Marco, Glombitza, Jonas, Gobbi, Fabian, Gollan, Fernando, Golup, Geraldina, G��mez Berisso, Mariano, G��mez Vitale, Primo F., Gongora, Juan Pablo, Gonz��lez, Juan Manuel, Gonzalez, Nicolas Martin, Goos, Isabel, Gora, Dariusz, Gorgi, Alessio, Gottowik, Marvin, Grubb, Trent D., Guarino, Fausto, Guedes, Germano, Guido, Eleonora, Hahn, Steffen, Hamal, Petr, Hampel, Mat��as Rolf, Hansen, Patricia Mar��a, Harari, Diego, Harvey, Violet M., Haungs, Andreas, Hebbeker, Thomas, Heck, Dieter, Hill, Gary C., Hojvat, Carlos, H��randel, J��rg, Horvath, Pavel, Hrabovsky, Miroslav, Huege, Tim, Insolia, Antonio, Isar, Paula Gina, Janecek, Petr, Johnsen, Jeffrey A., Jury��ek, Jakub, K��p��, Alex, Kampert, Karl-Heinz, Karastathis, Nikolaos, Keilhauer, Bianca, Kemp, Julian, Khakurdikar, Abha, Kizakke Covilakam, Varada Varma, Klages, Hans, Kleifges, Matthias, Kleinfeller, Jonny, K��pke, Marcel, Kunka, Norbert, Lago, Bruno L., Lang, Rodrigo Guedes, Langner, Niklas, Leigui De Oliveira, Marcelo Augusto, Lenok, Vladimir, Letessier-Selvon, Antoine, Lhenry-Yvon, Isabelle, Lo Presti, Domenico, LOPES, Luis, L��pez, Rebeca, Lu, Lu, Luce, Quentin, Lundquist, Jon Paul, Machado Payeras, Allan, Mancarella, Giovanni, Mandat, Dusan, Manning, Bradley C., Manshanden, Julien, Mantsch, Paul, Marafico, Sullivan, Mariazzi, Analisa, Maris, Ioana Codrina, Marsella, Giovanni, Martello, Daniele, Martinelli, Sara, Mart��nez Bravo, Oscar, Mastrodicasa, Massimo, Mathes, Hermann-Josef, Matthews, James, Matthiae, Giorgio, Mayotte, Eric, Mazur, Peter, Medina-Tanco, Gustavo, Melo, Diego, Menshikov, Alexander, Merenda, Kevin-Druis, Michal, Stanislav, Micheletti, Maria Isabel, Miramonti, Lino, Mollerach, Silvia, Montanet, Fran��ois, Morello, Carlo, Mostafa, Miguel, M��ller, Ana L., Muller, Marcio Aparecido, Mulrey, Katharine, Mussa, Roberto, Muzio, Marco Stein, Namasaka, Wilson M., Nasr-Esfahani, Alina, Nellen, Lukas, Niculescu-Oglinzanu, Mihai, Niechciol, Marcus, Nitz, Dave, Nosek, Dalibor, Novotn��, Vladim��r, Nozka, Libor, Nucita, Achille, Nunez, Luis A., Palatka, Miroslav, Pallotta, Juan, Papenbreer, Philipp, Parente, Gonzalo, Parra, Alejandra, Pawlowsky, Jannis, Pech, Miroslav, Pedreira, Francisco, P��kala, Jan, Pelayo, Rodrigo, Pe��a-Rodr��guez, Jes��s, Pereira Martins, Edyvania Emily, Perez Armand, Johnnier, P��rez Bertolli, Carmina, Perlin, Mat��as, Perrone, Lorenzo, Petrera, Sergio, Pierog, Tanguy, Pimenta, M��rio, Pirronello, Valerio, Platino, Manuel, Pont, Bjarni, Pothast, Mart, Privitera, Paolo, Prouza, Michael, Puyleart, Andrew, Querchfeld, Sven, Rautenberg, Julian, Ravignani, Diego, Reininghaus, Maximilian, Ridky, Jan, Riehn, Felix, Risse, Markus, Rizi, Vincenzo, Rodrigues De Carvalho, Washington, Rodriguez Rojo, Jorge Rub��n, Roncoroni, Mat��as J., Rossoni, Simone, Roth, Markus, Roulet, Esteban, Rovero, Adrian, Ruehl, Philip, Saftoiu, Alexandra, Salamida, Francesco, Salazar, Humberto Ibarguen, Salina, Gaetano, Sanabria Gomez, Jose, S��nchez, Federico Andr��s, Santos, Edivaldo Moura, Santos, Eva, Sarazin, Fred, Sarmento, Raul, Sarmiento-Cano, Christian, Sato, Ricardo, Savina, Pierpaolo, Sch��fer, Christoph M., Scherini, Viviana, Schieler, Harald, Schimassek, Martin, Schimp, Michael, Schl��ter, Felix, Schmidt, David, Scholten, Olaf, Schovanek, Petr, Schr��der, Frank G., Schr��der, Sonja, Schulte, Josina, Sciutto, Sergio, Scornavacche, Marina, Segreto, Alberto, Sehgal, Srijan, Shellard, Ronald C., Sigl, Guenter, Silli, Gaia, Sima, Octavian, Smida, Radomir, Sommers, Paul, Soriano, Jorge F., Souchard, Julien, Squartini, Ruben, Stadelmaier, Maximilian, Stanca, Denis, Stani��, Samo, Stasielak, Jaroslaw, Stassi, Patrick, Streich, Alexander, Su��rez-Dur��n, Mauricio, Sudholz, Tristan, Suomijarvi, Tiina, Supanitsky, A. Daniel, Szadkowski, Zbigniew, Tapia, Alex, Taricco, Carla, Timmermans, Charles, Tkachenko, Olena, Tobiska, Petr, Todero Peixoto, Carlos J., Tom��, Bernardo, Torr��s, Zo��, Travaini, Andres, Travnicek, Petr, Trimarelli, Caterina, Tueros, Matias, Ulrich, Ralf, Unger, Michael, Vaclavek, Luk��, Vacula, Martin, Vald��s Galicia, Jose F., Valore, Laura, Varela, Enrique, V��squez-Ram��rez, Adriana, Veberic, Darko, Ventura, Cynthia, Vergara Quispe, Indira D., Verzi, Valerio, Vicha, Jakub, Vink, Jacco, Vorobiov, Serguei, Wahlberg, Hernan, Watanabe, Clara Keiko Oliveira, Watson, Alan, Weber, Marc, Weindl, Andreas, Wiencke, Lawrence, Wilczy��ski, Henryk, Wirtz, Marcus, Wittkowski, David, Wundheiler, Brian, Yushkov, Alexey, Zapparrata, Orazio, Zas, Enrique, Zavrtanik, Danilo, Zavrtanik, Marko, and Zehrer, Lukas
Subjects: Physics, Pierre Auger Observatory, Polarity (physics), Astronomy, Astrophysics, Lightning, Lightning strike, Altitude, Experimental High Energy Physics, Light emission, Satellite, High Energy Physics, ddc:620, Ionosphere, Engineering & allied operations
Abstract: Since 2013, the four sites of the Fluorescence Detector (FD) of the Pierre Auger Observatory record ELVES with a dedicated trigger. These UV light emissions are correlated to distant lightning strikes. The length of recorded traces has been increased from 100 $\mu$s (2013), to 300 $\mu$s (2014-16), to 900 $\mu$s (2017-present), to progressively extend the observation of the light emission towards the vertical of the causative lightning and beyond. A large fraction of the observed events shows double ELVES within the time window, and, in some cases, even more complex structures are observed. The nature of the multi-ELVES is not completely understood but may be related to the different types of lightning in which they are originated. For example, it is known that Narrow Bipolar Events can produce double ELVES, and Energetic In-cloud Pulses, occurring between the main negative and upper positive charge layer of clouds, can induce double and even quadruple ELVES in the ionosphere. This report shows the seasonal and daily dependence of the time gap, amplitude ratio, and correlation between the pulse widths of the peaks in a sample of 1000+ multi-ELVES events recorded during the period 2014-20. The events have been compared with data from other satellite and ground-based sensing devices to study the correlation of their properties with lightning observables such as altitude and polarity.
Published: 2022

25. On the Location of the gamma-Ray Outburst Emission in the BL Lacertae Object AO 0235 + 164 Through Observations Across the Electromagnetic Spectrum

Author: Agudo, Ivan, Marscher, Alan P, Jorstad, Svetlana G, Larionov, Valeri M, Gomez, Jose L, Laehteenmaeki, Anne, Smith, Paul S, Nilsson, Kari, Readhead, Anthony C. S, Aller, Margo F, Heidt, Jochien, Gurwell, Mark, Thum, Clemens, Wehrle, Ann E, Nikolashvili, Maria G, Aller, Hugh D, Benitez, Erika, Blinov, Dmitriy A, Hagen-Thorn, Vladimir A, Hiriart, David, Jannuzi, Buell T, Joshi, Manasvita, Kimeridze, Givi N, Kurtanidze, Omar M, and Kurtanidze, Sofia O
Subjects: Astrophysics
Abstract: We present observations of a major outburst at centimeter, millimeter, optical, X-ray, and gamma-ray wavelengths of the BL Lacertae object AO 0235+164. We analyze the timing of multi-waveband variations in the flux and linear polarization, as well as changes in Very Long Baseline Array images at A = 7 mm with approx.0.15 milliarcsec resolution. The association of the events at different wavebands is confirmed at high statistical significance by probability arguments and Monte Carlo simulations. A series of sharp peaks in optical linear polarization, as well as a pronounced maximum in the 7 mm polarization of a superluminal jet knot, indicate rapid fluctuations in the degree of ordering of the magnetic field. These results lead us to conclude that the outburst occurred in the jet both in the quasi-stationary "core" and in the superluminal knot, both parsecs downstream of the supermassive black hole. We interpret the outburst as a consequence of the propagation of a disturbance, elongated along the line of sight by light-travel time delays, that passes through a standing recollimation shock in the core and propagates down the jet to create the superluminal knot. The multi-wavelength light curves vary together on long timescales (months/ years), but the correspondence is poorer on shorter timescales. This, as well as the variability of the polarization and the dual location of the outburst, agrees with the expectations of a multi-zone emission model in which turbulence plays a major role in modulating the synchrotron and inverse Compton fluxes.
Published: 2011
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26. X-ray Dips Followed by Superluminal Ejections as Evidence for An Accretion Disc Feeding the Jet in A Radio Galaxy

Author: Marscher, Alan P, Jorstad, Svetlana G, Gomez, Jose-Luis, Aller, Margo F, Terasranta, Harri, Lister, Matthew L, and Stirling, Alastair, M
Subjects: Astrophysics
Abstract: Accretion onto black holes is thought to power the relativistic jets and other high-energy phenomena in both active galactic nuclei (AGNs) and the "microquasar" binary systems located in our Galaxy. However, until now there has been insufficient multifrequency monitoring to establish a direct observational link between the black hole and the jet in an AGE. This contrasts with the case of microquasars, in which superluminal features appear and propagate down the radio jet shortly after sudden decreases in the X-ray flux. Such an X-ray dip is most likely caused by the disappearance of a section of the inner accretion disc, part of which falls past the event horizon and the remainder of which is injected into the jet. This infusion of energy generates a disturbance that propagates down the jet, creating the appearance of a superluminal bright spot. Here we report the results of three years of intensive monitoring of the X-ray and radio emission of the Seyfert-like radio galaxy 3C 120. As in the case of microquasars, dips in the X-ray emission are followed by ejections of bright superluminal knots in the radio jet. Comparison of the characteristic length and time scales allows us to infer that the rotational states of the black holes in these two objects are different.
Published: 2002

27. Jet Stability and the Generation of Superluminal and Stationary Components

Author: Agudo, Ivan, Gomez, Jose-Luis, Marti, Jose-Maria, Ibanez, Jose-Maria, Marscher, Alan P, Alberdi, Antonio, Aloy, Miguel-Angel, and Hardee, Philip E
Subjects: Astrophysics
Abstract: We present a numerical simulation of the response of an expanding relativistic jet to the ejection of a superluminal component. The simulation has been performed with a relativistic time-dependent hydrodynamical code from which simulated radio maps are computed by integrating the transfer equations for synchrotron radiation. The interaction of the superluminal component with the underlying jet results in the formation of multiple conical shocks behind the main perturbation. These trailing components can be easily distinguished because they appear to be released from the primary superluminal component instead of being ejected from the core. Their oblique nature should also result in distinct polarization properties. Those appearing closer to the core show small apparent motions and a very slow secular decrease in brightness and could be identified as stationary components. Those appearing farther downstream are weaker and can reach superluminal apparent motions. The existence of these trailing components indicates that not all observed components necessarily represent major perturbations at the jet inlet; rather, multiple emission components can be generated by a single disturbance in the jet. While the superluminal component associated with the primary perturbation exhibits a rather stable pattern speed, trailing components have velocities that increase with distance from the core but move at less than the jet speed. The trailing components exhibit motion and structure consistent with the triggering of pinch modes by the superluminal component. The increase in velocity of the trailing components is an indirect consequence of the acceleration of the expanding fluid, which is assumed to be relativistically hot; if observed, such accelerations would therefore favor an electron-positron (as opposed to proton rest mass) dominated jet.
Published: 2001
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28. Upper limits to the detection of ammonia from protoplanetary disks around HL Tauri and L1551-IRS 5

Author: Gomez, Jose F, Torrelles, Jose M, Ho, Paul T. P, Rodriguez, Luis F, and Canto, Jorge
Subjects: Astrophysics
Abstract: We present NH3(1, 1) and (2, 2) observations of the young stellar sources HL Tau and L1551-IRS 5 using the VLA in its B-configuration, which provides an angular resolution of about 0.4 arcsec (about 50 AU at 140 pc) at 1.3 cm wavelength. Our goal was to detect and resolve circumstellar molecular disks with radius of the order of 100 AU around these two sources. No ammonia emission was detected toward either of them. The 3-sigma levels were 2.7 mJy/beam and 3.9 mJy/beam for HL Tau and L1551-IRS 5, respectively, with a velocity resolution of about 5 km/s. With this nondetection, we estimate upper limits to the mass of the proposed protoplanetary molecular disks (within a radius of 10 AU from the central stars) on the order of 0.02/(X(NH3)/10 exp -8) solar mass for HL Tau and 0.1/(X(NH3)/10 exp -8) solar mass for L1551-IRS 5.
Published: 1993
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29. A flattened cloud core in NGC 2024

Author: Ho, Paul T. P, Peng, Yun-Lou, Torrelles, Jose M, Gomez, Jose F, Rodriguez, Luis F, and Canto, Jorge
Subjects: Astrophysics
Abstract: The (J, K) (1, 1) and (2, 2) NH3 lines were mapped toward a molecular cloud core in NGC 2024 using the VLA in its C/D-configuration. This region is associated with one of the most highly collimated molecular outflows. We find that the molecular condensations associated with the far-infrared sources FIR 5, FIR 6, and FIR 7 have kinetic temperatures of about 40 K. We also find line broadening toward FIR 6 and FIR 7. This suggests that these condensations may not be protostars heated by gravitational energy released during collapse but that they have an internal heating source. A flattened structure of ammonia emission is found extending parallel to the unipolar CO outflow structure, but displaced systematically to the east. If the NH3 emission traces the denser gas environment, there is no evidence that a dense gas structure is confining the molecular outflow. Instead, the location of the high-velocity outflow along the surface of the NH3 structure suggests that a wind is sweeping material from the surface of this elongated cloud core.
Published: 1993
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30. A survey for water maser emission towards planetary nebulae. New detection in IRAS 17347-3139

Author: Torrelles, Jose, Gomez, Jose, Miranda, Luis, De Gregorio-Monsalvo, Itziar, Anglada, Guillem, Cesaroni, Riccardo, Gomez, Yolanda, and De Gregorio‐Monsalvo, Itziar
Subjects: Physics, Spectral index, Astrophysics (astro-ph), FOS: Physical sciences, Astronomy and Astrophysics, Torus, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Spatial distribution, Ellipse, Planetary nebula, law.invention, Space and Planetary Science, law, Ionization, Asymptotic giant branch, Astrophysics::Solar and Stellar Astrophysics, Maser, Astrophysics::Galaxy Astrophysics
Abstract: We report on a water maser survey towards a sample of 27 planetary nebulae (PNe) using the Robledo de Chavela and Medicina single-dish antennas, as well as the Very Large Array (VLA). Two detections have been obtained: the already known water maser emission in K 3-35, and a new cluster of masers in IRAS 17347-3139. This low rate of detections is compatible with the short life-time of water molecules in PNe (~100 yr). The water maser cluster at IRAS 17347-3139 are distributed on a ellipse of size ~ 0.2" x 0.1", spatially associated with compact 1.3 cm continuum emission (simultaneously observed with the VLA). From archive VLA continuum data at 4.9, 8.4, and 14.9 GHz, a spectral index alpha = 0.76 +- 0.03 is derived for this radio source, which is consistent with either a partially optically thick ionized region or with an ionized wind. However, the latter scenario can be ruled out on mass-loss considerations, thus indicating that this source is probably a young PN. The spatial distribution and the radial velocities of the water masers are suggestive of a rotating and expanding maser ring, tracing the innermost regions of a torus formed at the end of the AGB phase. Given that the 1.3 cm continuum emission peak is located near one of the tips of the major axis of the ellipse of masers, we speculate on a possible binary nature of IRAS 17347-3139, where the radio continuum emission could belong to one of the components and the water masers would be associated with a companion., Accepted by The Astrophysical Journal. 25 pages, 6 figures
Published: 2003

31. Large-scale and multipolar anisotropies of cosmic rays detected at the Pierre Auger Observatory with energies above 4 EeV

Author: Pierre Auger Collaboration, Almeida, Rogerio de, Abreu, Pedro, Aglietta, Marco, Albury, Justin M., Allekotte, Ingomar, Almela, Alejandro, Alvarez-Muniz, Jaime, Alves Batista, Rafael, Anastasi, Gioacchino Alex, Anchordoqui, Luis A., Andrada, Belén, Andringa, Sofia, Aramo, Carla, Araújo Ferreira, Paulo Ricardo, Arteaga Velazquez, Juan Carlos, Asorey, Hernán Gonzalo, Assis, Pedro, Avila, Gualberto, Badescu, Alina Mihaela, Bakalova, Alena, Balaceanu, Alexandru, Barbato, Felicia, Barreira Luz, Ricardo Jorge, Becker, Karl-Heinz, Bellido, Jose A., Berat, Corinne, Bertaina, Mario Edoardo, Bertou, Xavier, Biermann, Peter L., Binet, Virginia, Bismark, Kathrin, Bister, Teresa, Biteau, Jonathan, Blazek, Jiri, Bleve, Carla, Bohacova, Martina, boncioli, denise, Bonifazi, Carla, Bonneau Arbeletche, Luan, Borodai, Nataliia, Botti, Ana Martina, Brack, Jeffrey, Bretz, Thomas, Brichetto Orchera, P. Gabriel, Briechle, Florian Lukas, Buchholz, Peter, Bueno, Antonio, Buitink, Stijn, Buscemi, Mario, Büsken, Max, Caballero-Mora, Karen S., Caccianiga, Lorenzo, Canfora, Fabrizia, Caracas, Ioana, Carceller, Juan Miguel, Caruso, Rossella, Castellina, Antonella, Catalani, Fernando, Cataldi, Gabriella, Cazon, Lorenzo, Cerda, Marcos, Chinellato, Jose Augusto, Chudoba, Jiri, Chytka, Ladislav, Clay, Roger W., Cobos Cerutti, Agustín, Colalillo, Roberta, Coleman, Alan, Coluccia, Maria Rita, Conceição, Rúben, Condorelli, Antonio, Consolati, Giovanni, Contreras, Fernando, Convenga, Fabio, Correia dos Santos, Diego, Covault, Corbin, Dasso, Sergio, Daumiller, Kai, Dawson, Bruce R., Day, Jarryd A., Almeida, Rogerio M. de, Jesús, Joaquín de, Jong, Sijbrand J. de, De Mauro, Giuseppe, Mello Neto, João de, De Mitri, Ivan, Oliveira, Jaime de, Oliveira Franco, Danelise de, Palma, Francesco de, Souza, Vitor de, De Vito, Emanuele, Río, Mariano del, Deligny, Olivier, Deval, Luca, Matteo, Armando di, Dobrigkeit, Carola, D'Olivo, Juan Carlos, Domingues Mendes, Luis Miguel, Anjos, Rita dos, Santos, Diego dos, Dova, Maria Teresa, Ebr, Jan, Engel, Ralph, Epicoco, Italo, Erdmann, Martin, Escobar, Carlos O., Etchegoyen, Alberto, Falcke, Heino, Farmer, John, Farrar, Glennys R., Fauth, Anderson, Fazzini, Norberto, Feldbusch, Fridtjof, Fenu, Francesco, Fick, Brian, Figueira, Juan Manuel, Filipcic, Andrej, Fitoussi, Thomas, Fodran, Tomáš, Freire, Martín Miguel, Fujii, Toshihiro, Fuster, Alan, Galea, Cristina, Galelli, Claudio, García, Beatriz, García Vegas, Adrianna Luz, Gemmeke, Hartmut, Gesualdi, Flavia, Gherghel-Lascu, Alexandru, Ghia, Piera Luisa, GIACCARI, Ugo, Giammarchi, Marco, Glombitza, Jonas, Gobbi, Fabian, Gollan, Fernando, Golup, Geraldina, Gómez Berisso, Mariano, Gómez Vitale, Primo F., Gongora, Juan Pablo, González, Juan Manuel, Gonzalez, Nicolas Martin, Goos, Isabel, Gora, Dariusz, Gorgi, Alessio, Gottowik, Marvin, Grubb, Trent D., Guarino, Fausto, Guedes, Germano, Guido, Eleonora, Hahn, Steffen, Hamal, Petr, Hampel, Matías Rolf, Hansen, Patricia María, Harari, Diego, Harvey, Violet M., Haungs, Andreas, Hebbeker, Thomas, Heck, Dieter, Hill, Gary C., Hojvat, Carlos, Hörandel, Jörg, Horvath, Pavel, Hrabovsky, Miroslav, Huege, Tim, Insolia, Antonio, Isar, Paula Gina, Janecek, Petr, Johnsen, Jeffrey A., Juryšek, Jakub, Kääpä, Alex, Kampert, Karl-Heinz, Karastathis, Nikolaos, Keilhauer, Bianca, Kemp, Julian, Khakurdikar, Abha, Kizakke Covilakam, Varada Varma, Klages, Hans, Kleifges, Matthias, Kleinfeller, Jonny, Köpke, Marcel, Kunka, Norbert, Lago, Bruno L., Lang, Rodrigo Guedes, Langner, Niklas, Leigui de Oliveira, Marcelo Augusto, Lenok, Vladimir, Letessier-Selvon, Antoine, Lhenry-Yvon, Isabelle, Lo Presti, Domenico, LOPES, Luis, López, Rebeca, Lu, Lu, Luce, Quentin, Lundquist, Jon Paul, Machado Payeras, Allan, Mancarella, Giovanni, Mandat, Dusan, Manning, Bradley C., Manshanden, Julien, Mantsch, Paul, Marafico, Sullivan, Mariazzi, Analisa, Maris, Ioana Codrina, Marsella, Giovanni, Martello, Daniele, Martinelli, Sara, Martínez Bravo, Oscar, Mastrodicasa, Massimo, Mathes, Hermann-Josef, Matthews, James, Matthiae, Giorgio, Mayotte, Eric, Mazur, Peter, Medina-Tanco, Gustavo, Melo, Diego, Menshikov, Alexander, Merenda, Kevin-Druis, Michal, Stanislav, Micheletti, Maria Isabel, Miramonti, Lino, Mollerach, Silvia, Montanet, François, Morello, Carlo, Mostafa, Miguel, Müller, Ana L., Muller, Marcio Aparecido, Mulrey, Katharine, Mussa, Roberto, Muzio, Marco Stein, Namasaka, Wilson M., Nasr-Esfahani, Alina, Nellen, Lukas, Niculescu-Oglinzanu, Mihai, Niechciol, Marcus, Nitz, Dave, Nosek, Dalibor, Novotný, Vladimír, Nozka, Libor, Nucita, Achille, Nunez, Luis A., Palatka, Miroslav, Pallotta, Juan, Papenbreer, Philipp, Parente, Gonzalo, Parra, Alejandra, Pawlowsky, Jannis, Pech, Miroslav, Pedreira, Francisco, Pękala, Jan, Pelayo, Rodrigo, Peña-Rodríguez, Jesús, Pereira Martins, Edyvania Emily, Perez Armand, Johnnier, Pérez Bertolli, Carmina, Perlin, Matías, Perrone, Lorenzo, Petrera, Sergio, Pierog, Tanguy, Pimenta, Mário, Pirronello, Valerio, Platino, Manuel, Pont, Bjarni, Pothast, Mart, Privitera, Paolo, Prouza, Michael, Puyleart, Andrew, Querchfeld, Sven, Rautenberg, Julian, Ravignani, Diego, Reininghaus, Maximilian, Ridky, Jan, Riehn, Felix, Risse, Markus, Rizi, Vincenzo, Rodrigues de Carvalho, Washington, Rodriguez Rojo, Jorge Rubén, Roncoroni, Matías J., Rossoni, Simone, Roth, Markus, Roulet, Esteban, Rovero, Adrian, Ruehl, Philip, Saftoiu, Alexandra, Salamida, Francesco, Salazar, Humberto Ibarguen, Salina, Gaetano, Sanabria Gomez, Jose, Sánchez, Federico Andrés, Santos, Edivaldo Moura, Santos, Eva, Sarazin, Fred, Sarmento, Raul, Sarmiento-Cano, Christian, Sato, Ricardo, Savina, Pierpaolo, Schäfer, Christoph M., Scherini, Viviana, Schieler, Harald, Schimassek, Martin, Schimp, Michael, Schlüter, Felix, Schmidt, David, Scholten, Olaf, Schovanek, Petr, Schröder, Frank G., Schröder, Sonja, Schulte, Josina, Sciutto, Sergio, Scornavacche, Marina, Segreto, Alberto, Sehgal, Srijan, Shellard, Ronald C., Sigl, Guenter, Silli, Gaia, Sima, Octavian, Smida, Radomir, Sommers, Paul, Soriano, Jorge F., Souchard, Julien, Squartini, Ruben, Stadelmaier, Maximilian, Stanca, Denis, Stanič, Samo, Stasielak, Jaroslaw, Stassi, Patrick, Streich, Alexander, Suárez-Durán, Mauricio, Sudholz, Tristan, Suomijarvi, Tiina, Supanitsky, A. Daniel, Szadkowski, Zbigniew, Tapia, Alex, Taricco, Carla, Timmermans, Charles, Tkachenko, Olena, Tobiska, Petr, Todero Peixoto, Carlos J., Tomé, Bernardo, Torrès, Zoé, Travaini, Andres, Travnicek, Petr, Trimarelli, Caterina, Tueros, Matias, Ulrich, Ralf, Unger, Michael, Vaclavek, Lukáš, Vacula, Martin, Valdés Galicia, Jose F., Valore, Laura, Varela, Enrique, Vásquez-Ramírez, Adriana, Veberic, Darko, Ventura, Cynthia, Vergara Quispe, Indira D., Verzi, Valerio, Vicha, Jakub, Vink, Jacco, Vorobiov, Serguei, Wahlberg, Hernan, Watanabe, Clara Keiko Oliveira, Watson, Alan, Weber, Marc, Weindl, Andreas, Wiencke, Lawrence, Wilczyński, Henryk, Wirtz, Marcus, Wittkowski, David, Wundheiler, Brian, Yushkov, Alexey, Zapparrata, Orazio, Zas, Enrique, Zavrtanik, Danilo, Zavrtanik, Marko, and Zehrer, Lukas
Subjects: Physics, Pierre Auger Observatory, Astrophysics::High Energy Astrophysical Phenomena, media_common.quotation_subject, Astronomy, Astrophysics::Instrumentation and Methods for Astrophysics, Spectral density, Cosmic ray, Astrophysics, Azimuth, Sky, Observatory, Experimental High Energy Physics, ddc:530, High Energy Physics, Right ascension, Zenith, media_common
Abstract: More than half a century after the discovery of ultra-high energy cosmic rays (UHECRs), their origin is still an open question. The study of anisotropies in the arrival directions of such particles is an essential ingredient to solve this puzzle. We update our previous analysis of large-scale anisotropies observed by the Pierre Auger Observatory using the latest data collected before the AugerPrime upgrade. We select events with zenith angles up to 80 degrees, implying a sky coverage of 85$\%$, and energies above 4 EeV, for which the surface detector of the Observatory is fully efficient. Dipolar and quadrupolar amplitudes are evaluated through a combined Fourier analysis of the event count rate in right ascension and azimuth. The analysis is performed in three energy bins with boundaries at 4, 8, 16 and 32 EeV and two additional cumulative bins with energies above 8 and 32 EeV. The most significant signal is a dipolar modulation in right ascension for energies above 8 EeV, as previously reported, with statistical significance of $6.6\sigma$. Additionally, we report the measurements of the angular power spectrum for the same energy bins with the same dataset.

32. Downward Terrestrial Gamma-ray Flashes at the Pierre Auger Observatory?

Author: Colalillo, R., Abreu, P., Aglietta, M., Albury, J. M., Allekotte, I., Almela, A., Alvarez-Muñiz, J., Alves Batista, R., Anastasi, G. A., Anchordoqui, L., Andrada, B., Andringa, S., Aramo, C., Araújo Ferreira, P. R., Arteaga Velázquez, J. C., Asorey, H., Assis, P., Avila, G., Badescu, A. M., Bakalova, A., Balaceanu, A., Barbato, F., Barreira Luz, R. J., Becker, K. H., Bellido, J. A., Berat, C., Bertaina, M. E., Bertou, X., Biermann, P. L., Binet, V., Bismark, K., Bister, T., Biteau, J., Blazek, J., Bleve, C., Boháčová, M., Boncioli, D., Bonifazi, C., Bonneau Arbeletche, L., Borodai, N., Botti, A. M., Brack, J., Bretz, T., Brichetto Orchera, P. G., Briechle, F. L., Buchholz, P., Bueno, A., Buitink, S., Buscemi, M., Büsken, M., Caballero-Mora, K. S., Caccianiga, L., Canfora, F., Caracas, I., Carceller, J. M., Caruso, R., Castellina, A., Catalani, F., Cataldi, G., Cazon, L., Cerda, M., Chinellato, J. A., Chudoba, J., Chytka, L., Clay, R. W., Cobos Cerutti, A. C., Coleman, A., Coluccia, M. R., Ruben Conceição, Condorelli, A., Consolati, G., Contreras, F., Convenga, F., Correia Dos Santos, D., Covault, C. E., Dasso, S., Daumiller, K., Dawson, B. R., Day, J. A., Almeida, R. M., Jesús, J., Jong, S. J., Mauro, G., Mello Neto, J. R. T., Mitri, I., Oliveira, J., Oliveira Franco, D., Palma, F., Souza, V., Vito, E., Del Río, M., Deligny, O., Deval, L., Di Matteo, A., Dobrigkeit, C., D’olivo, J. C., Domingues Mendes, L. M., Dos Anjos, R. C., Dos Santos, D., Dova, M. T., Ebr, J., Engel, R., Epicoco, I., Erdmann, M., Escobar, C. O., Etchegoyen, A., Falcke, H., Farmer, J., Farrar, G., Fauth, A. C., Fazzini, N., Feldbusch, F., Fenu, F., Fick, B., Figueira, J. M., Filipčič, A., Fitoussi, T., Fodran, T., Freire, M. M., Fujii, T., Fuster, A., Galea, C., Galelli, C., García, B., Garcia Vegas, A. L., Gemmeke, H., Gesualdi, F., Gherghel-Lascu, A., Ghia, P. L., Giaccari, U., Giammarchi, M., Glombitza, J., Gobbi, F., Gollan, F., Golup, G., Gómez Berisso, M., Gómez Vitale, P. F., Gongora, J. P., González, J. M., González, N., Goos, I., Góra, D., Gorgi, A., Gottowik, M., Grubb, T. D., Guarino, F., Guedes, G. P., Guido, E., Hahn, S., Hamal, P., Hampel, M. R., Hansen, P., Harari, D., Harvey, V. M., Haungs, A., Hebbeker, T., Heck, D., Hill, G. C., Hojvat, C., Hörandel, J. R., Horvath, P., Hrabovský, M., Huege, T., Insolia, A., Isar, P. G., Janecek, P., Johnsen, J. A., Jurysek, J., Kääpä, A., Kampert, K. H., Karastathis, N., Keilhauer, B., Kemp, J., Khakurdikar, A., Kizakke Covilakam, V. V., Klages, H. O., Kleifges, M., Kleinfeller, J., Köpke, M., Kunka, N., Lago, B. L., Lang, R. G., Langner, N., Leigui Oliveira, M. A., Lenok, V., Letessier-Selvon, A., Lhenry-Yvon, I., Lo Presti, D., Lopes, L., López, R., Lu, L., Luce, Q., Lundquist, J. P., Machado Payeras, A., Mancarella, G., Mandat, D., Manning, B. C., Manshanden, J., Mantsch, P., Marafico, S., Mariazzi, A. G., Mariş, I. C., Marsella, G., Martello, D., Martinelli, S., Martínez Bravo, O., Mastrodicasa, M., Mathes, H. J., Matthews, J., Matthiae, G., Mayotte, E., Mazur, P. O., Medina-Tanco, G., Melo, D., Menshikov, A., Merenda, K. -D, Michal, S., Micheletti, M. I., Miramonti, L., Mollerach, S., Montanet, F., Morello, C., Mostafá, M., Müller, A. L., Muller, M. A., Mulrey, K., Mussa, R., Muzio, M., Namasaka, W. M., Nasr-Esfahani, A., Nellen, L., Niculescu-Oglinzanu, M., Niechciol, M., Nitz, D., Nosek, D., Novotny, V., Nožka, L., Nucita, A., Núñez, L. A., Palatka, M., Pallotta, J., Papenbreer, P., Parente, G., Parra, A., Pawlowsky, J., Pech, M., Pedreira, F., Pȩkala, J., Pelayo, R., Peña-Rodriguez, J., Pereira Martins, E. E., Perez Armand, J., Pérez Bertolli, C., Perlin, M., Perrone, L., Petrera, S., Pierog, T., Pimenta, M., Pirronello, V., Platino, M., Pont, B., Pothast, M., Privitera, P., Prouza, M., Puyleart, A., Querchfeld, S., Rautenberg, J., Ravignani, D., Reininghaus, M., Ridky, J., Riehn, F., Risse, M., Rizi, V., Rodrigues Carvalho, W., Rodriguez Rojo, J., Roncoroni, M. J., Rossoni, S., Roth, M., Roulet, E., Rovero, A. C., Ruehl, P., Saftoiu, A., Salamida, F., Salazar, H., Salina, G., Sanabria Gomez, J. D., Sánchez, F., Santos, E. M., Santos, E., Sarazin, F., Sarmento, R., Sarmiento-Cano, C., Sato, R., Savina, P., Schäfer, C. M., Scherini, V., Schieler, H., Schimassek, M., Schimp, M., Schlüter, F., Schmidt, D., Scholten, O., Schovánek, P., Schröder, F. G., Schröder, S., Schulte, J., Sciutto, S. J., Scornavacche, M., Segreto, A., Sehgal, S., Shellard, R. C., Sigl, G., Silli, G., Sima, O., Šmída, R., Sommers, P., Soriano, J. F., Souchard, J., Squartini, R., Stadelmaier, M., Stanca, D., Stanič, S., Stasielak, J., Stassi, P., Streich, A., Suárez-Durán, M., Sudholz, T., Suomijärvi, T., Supanitsky, A. D., Szadkowski, Z., Tapia, A., Taricco, C., Timmermans, C., Tkachenko, O., Tobiska, P., Todero Peixoto, C. J., Tomé, B., Torrès, Z., Travaini, A., Travnicek, P., Trimarelli, C., Tueros, M., Ulrich, R., Unger, M., Vaclavek, L., Vacula, M., Valdés Galicia, J. F., Valore, L., Varela, E., Vásquez-Ramírez, A., Veberič, D., Ventura, C., Vergara Quispe, I. D., Verzi, V., Vicha, J., Vink, J., Vorobiov, S., Wahlberg, H., Watanabe, C., Watson, A. A., Weber, M., Weindl, A., Wiencke, L., Wilczyński, H., Wirtz, M., Wittkowski, D., Wundheiler, B., Yushkov, A., Zapparrata, O., Zas, E., Zavrtanik, D., Zavrtanik, M., Zehrer, L., Colalillo, Roberta, Abreu, Pedro, Aglietta, Marco, Albury, Justin M., Allekotte, Ingomar, Almela, Alejandro, Alvarez-Muniz, Jaime, Alves Batista, Rafael, Anastasi, Gioacchino Alex, Anchordoqui, Luis A., Andrada, Belén, Andringa, Sofia, Aramo, Carla, Araújo Ferreira, Paulo Ricardo, Arteaga Velazquez, Juan Carlo, Asorey, Hernán Gonzalo, Assis, Pedro, Avila, Gualberto, Badescu, Alina Mihaela, Bakalova, Alena, Balaceanu, Alexandru, Barbato, Felicia, Barreira Luz, Ricardo Jorge, Becker, Karl-Heinz, Bellido, Jose A., Berat, Corinne, Bertaina, Mario Edoardo, Bertou, Xavier, Biermann, Peter L., Binet, Virginia, Bismark, Kathrin, Bister, Teresa, Biteau, Jonathan, Blazek, Jiri, Bleve, Carla, Bohacova, Martina, Boncioli, Denise, Bonifazi, Carla, Bonneau Arbeletche, Luan, Borodai, Nataliia, Botti, Ana Martina, Brack, Jeffrey, Bretz, Thoma, Brichetto Orchera, P. Gabriel, Briechle, Florian Luka, Buchholz, Peter, Bueno, Antonio, Buitink, Stijn, Buscemi, Mario, Büsken, Max, Caballero-Mora, Karen S., Caccianiga, Lorenzo, Canfora, Fabrizia, Caracas, Ioana, Carceller, Juan Miguel, Caruso, Rossella, Castellina, Antonella, Catalani, Fernando, Cataldi, Gabriella, Cazon, Lorenzo, Cerda, Marco, Chinellato, Jose Augusto, Chudoba, Jiří, Chytka, Ladislav, Clay, Roger W, Cobos Cerutti, Agustín, Coleman, Alan, Coluccia, Maria Rita, Conceição, Rúben, Condorelli, Antonio, Consolati, Giovanni, Contreras, Fernando, Convenga, Fabio, Correia dos Santos, Diego, Covault, Corbin, Dasso, Sergio, Daumiller, Kai, Dawson, Bruce R., Day, Jarryd A., de Almeida, Rogerio M., de Jesús, Joaquín, de Jong, Sijbrand J., De Mauro, Giuseppe, de Mello Neto, João, De Mitri, Ivan, de Oliveira, Jaime, de Oliveira Franco, Danelise, de Palma, Francesco, de Souza, Vitor, De Vito, Emanuele, del Río, Mariano, Deligny, Olivier, Deval, Luca, di Matteo, Armando, Dobrigkeit, Carola, D'Olivo, Juan Carlo, Domingues Mendes, Luis Miguel, dos Anjos, Rita, dos Santos, Diego, Dova, Maria Teresa, Ebr, Jan, Engel, Ralph, Epicoco, Italo, Erdmann, Martin, Escobar, Carlos O., Etchegoyen, Alberto, Falcke, Heino, Farmer, John, Farrar, Glennys R., Fauth, Anderson, Fazzini, Norberto, Feldbusch, Fridtjof, Fenu, Francesco, Fick, Brian, Figueira, Juan Manuel, Filipcic, Andrej, Fitoussi, Thoma, Fodran, Tomáš, Freire, Martín Miguel, Fujii, Toshihiro, Fuster, Alan, Galea, Cristina, Galelli, Claudio, García, Beatriz, García Vegas, Adrianna Luz, Gemmeke, Hartmut, Gesualdi, Flavia, Gherghel-Lascu, Alexandru, Ghia, Piera Luisa, Giaccari, Ugo, Giammarchi, Marco, Glombitza, Jona, Gobbi, Fabian, Gollan, Fernando, Golup, Geraldina, Gómez Berisso, Mariano, Gómez Vitale, Primo F., Gongora, Juan Pablo, González, Juan Manuel, Gonzalez, Nicolas Martin, Goos, Isabel, Gora, Dariusz, Gorgi, Alessio, Gottowik, Marvin, Grubb, Trent D., Guarino, Fausto, Guedes, Germano, Guido, Eleonora, Hahn, Steffen, Hamal, Petr, Hampel, Matías Rolf, Hansen, Patricia María, Harari, Diego, Harvey, Violet M., Haungs, Andrea, Hebbeker, Thoma, Heck, Dieter, Hill, Gary C., Hojvat, Carlo, Hörandel, Jörg, Horvath, Pavel, Hrabovsky, Miroslav, Huege, Tim, Insolia, Antonio, Isar, Paula Gina, Janecek, Petr, Johnsen, Jeffrey A., Juryšek, Jakub, Kääpä, Alex, Kampert, Karl-Heinz, Karastathis, Nikolao, Keilhauer, Bianca, Kemp, Julian, Khakurdikar, Abha, Kizakke Covilakam, Varada Varma, Klages, Han, Kleifges, Matthia, Kleinfeller, Jonny, Köpke, Marcel, Kunka, Norbert, Lago, Bruno L., Lang, Rodrigo Guede, Langner, Nikla, Leigui de Oliveira, Marcelo Augusto, Lenok, Vladimir, Letessier-Selvon, Antoine, Lhenry-Yvon, Isabelle, Lo Presti, Domenico, Lopes, Lui, López, Rebeca, Lu, Lu, Luce, Quentin, Lundquist, Jon Paul, Machado Payeras, Allan, Mancarella, Giovanni, Mandat, Dusan, Manning, Bradley C., Manshanden, Julien, Mantsch, Paul, Marafico, Sullivan, Mariazzi, Analisa, Maris, Ioana Codrina, Marsella, Giovanni, Martello, Daniele, Martinelli, Sara, Martínez Bravo, Oscar, Mastrodicasa, Massimo, Mathes, Hermann-Josef, Matthews, Jame, Matthiae, Giorgio, Mayotte, Eric, Mazur, Peter, Medina-Tanco, Gustavo, Melo, Diego, Menshikov, Alexander, Merenda, Kevin-Drui, Michal, Stanislav, Micheletti, Maria Isabel, Miramonti, Lino, Mollerach, Silvia, Montanet, Françoi, Morello, Carlo, Mostafa, Miguel, Müller, Ana L., Muller, Marcio Aparecido, Mulrey, Katharine, Mussa, Roberto, Muzio, Marco Stein, Namasaka, Wilson M., Nasr-Esfahani, Alina, Nellen, Luka, Niculescu-Oglinzanu, Mihai, Niechciol, Marcu, Nitz, Dave, Nosek, Dalibor, Novotný, Vladimír, Nozka, Libor, Nucita, Achille, Nunez, Luis A., Palatka, Miroslav, Pallotta, Juan, Papenbreer, Philipp, Parente, Gonzalo, Parra, Alejandra, Pawlowsky, Janni, Pech, Miroslav, Pedreira, Francisco, Pękala, Jan, Pelayo, Rodrigo, Peña-Rodríguez, Jesú, Pereira Martins, Edyvania Emily, Perez Armand, Johnnier, Pérez Bertolli, Carmina, Perlin, Matía, Perrone, Lorenzo, Petrera, Sergio, Pierog, Tanguy, Pimenta, Mário, Pirronello, Valerio, Platino, Manuel, Pont, Bjarni, Pothast, Mart, Privitera, Paolo, Prouza, Michael, Puyleart, Andrew, Querchfeld, Sven, Rautenberg, Julian, Ravignani, Diego, Reininghaus, Maximilian, Ridky, Jan, Riehn, Felix, Risse, Marku, Rizi, Vincenzo, Rodrigues de Carvalho, Washington, Rodriguez Rojo, Jorge Rubén, Roncoroni, Matías J., Rossoni, Simone, Roth, Marku, Roulet, Esteban, Rovero, Adrian, Ruehl, Philip, Saftoiu, Alexandra, Salamida, Francesco, Salazar, Humberto Ibarguen, Salina, Gaetano, Sanabria Gomez, Jose, Sánchez, Federico André, Santos, Edivaldo Moura, Santos, Eva, Sarazin, Fred, Sarmento, Raul, Sarmiento-Cano, Christian, Sato, Ricardo, Savina, Pierpaolo, Schäfer, Christoph M., Scherini, Viviana, Schieler, Harald, Schimassek, Martin, Schimp, Michael, Schlüter, Felix, Schmidt, David, Scholten, Olaf, Schovanek, Petr, Schröder, Frank G., Schröder, Sonja, Schulte, Josina, Sciutto, Sergio, Scornavacche, Marina, Segreto, Alberto, Sehgal, Srijan, Shellard, Ronald C., Sigl, Guenter, Silli, Gaia, Sima, Octavian, Smida, Radomir, Sommers, Paul, Soriano, Jorge F., Souchard, Julien, Squartini, Ruben, Stadelmaier, Maximilian, Stanca, Deni, Stanič, Samo, Stasielak, Jaroslaw, Stassi, Patrick, Streich, Alexander, Suárez-Durán, Mauricio, Sudholz, Tristan, Suomijarvi, Tiina, Supanitsky, A. Daniel, Szadkowski, Zbigniew, Tapia, Alex, Taricco, Carla, Timmermans, Charle, Tkachenko, Olena, Tobiska, Petr, Todero Peixoto, Carlos J., Tomé, Bernardo, Torrès, Zoé, Travaini, Andre, Travnicek, Petr, Trimarelli, Caterina, Tueros, Matia, Ulrich, Ralf, Unger, Michael, Vaclavek, Lukáš, Vacula, Martin, Valdés Galicia, Jose F., Valore, Laura, Varela, Enrique, Vásquez-Ramírez, Adriana, Veberic, Darko, Ventura, Cynthia, Vergara Quispe, Indira D., Verzi, Valerio, Vicha, Jakub, Vink, Jacco, Vorobiov, Serguei, Wahlberg, Hernan, Watanabe, Clara Keiko Oliveira, Watson, Alan, Weber, Marc, Weindl, Andrea, Wiencke, Lawrence, Wilczyński, Henryk, Wirtz, Marcu, Wittkowski, David, Wundheiler, Brian, Yushkov, Alexey, Zapparrata, Orazio, Zas, Enrique, Zavrtanik, Danilo, Zavrtanik, Marko, and Zehrer, Lukas
Subjects: Physics, Pierre Auger Observatory, Astronomy, Astrophysics::High Energy Astrophysical Phenomena, Gamma ray, Cosmic ray, Electron, Astrophysics, Lightning, Experimental High Energy Physics, Thunderstorm, High Energy Physics, Atmospheric electricity, ddc:620, Event (particle physics), Engineering & allied operations
Abstract: At the Pierre Auger Observatory, designed primarily to study ultra-high-energy cosmic rays, phenomena related to atmospheric electricity are also observed. Particularly, events have been detected with the surface detector, characterized by long-lasting signals (tens of microseconds) and event footprints much larger (up to 200 km$^2$) than those produced by the highest energy cosmic rays. Moreover, some of them appear to be accompanied by smaller events occurring in the same area within about 1 ms and probably produced by the same phenomenon. A previously reported correlation with the World Wide Lightning Location Network, as well as the observation of very low-altitude clouds, confirm that such events are related to thunderstorms. An ad-hoc reconstruction points to high-energy particles being produced very close to the ground, suggesting that they originate from electrons accelerated to relativistic energies in strong electric fields inside low clouds, as is the case for terrestrial gamma-ray flashes above thunderstorms. A clear explanation of the observed phenomenon is hindered by two facts. One is that the rate of such events, detected serendipitously, is very small (less than 2 events/year) and decreases further after optimization of the surface detector trigger for low-energy shower-events. The second is that most events show a puzzling lack of signals in the central part of the footprint. We have studied in detail both effects and will present such studies here. We developed a strategy for a dedicated trigger to enhance the detection efficiency for these events associated with atmospheric-electricity events.

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32 results on '"Gomez, Jose A."'

1. Radio interferometric observations of candidate water-maser-emitting planetary nebulae

2. Multiwaveband Polarimetric Observations of 15 Active Galactic Nuclei at High Frequencies: Correlated Polarization Behavior

3. Statistical analysis of molecular line emission from T Tauri disk models

4. A sensitive survey for water maser emission towards Bok globules using the Robledo 70m antenna

5. A disk of dust and molecular gas around a high-mass protostar

6. Polarimetric Observations of 15 Active Galactic Nuclei at High Frequencies: Jet Kinematics from Bimonthly Monitoring with the Very Long Baseline Array

7. Molecular Line Emission from Accretion Disks Around YSOs

8. A survey for water maser emission towards planetary nebulae. New detection in IRAS 17347-3139

9. 3D Simulations of Relativistic Precessing Jets Probing the Structure of Superluminal Sources

10. Monthly 43 GHz VLBA Polarimetric Monitoring of 3C120 over 16 Epochs: Evidence for Trailing Shocks in a Relativistic Jet

11. Exact Solution for the Exterior Field of a Rotating Neutron Star

12. Ammonia observations of the nearby molecular cloud MBM 12

13. Space VLBI Observations of 3C371

14. Resolving Molecular Line Emission from Protoplanetary Disks: Observational Prospects for Disks Irradiated by Infalling Envelopes

15. Radio Emission from 3D Relativistic Hydrodynamic Jets: Observational Evidence of Jet Stratification

16. Simulations of Relativistic Jets with GENESIS

17. Far Ultraviolet Absolute Flux of alpha Virginis

18. Evidence Against the Sciama Model of Radiative Decay of Massive Neutrinos

19. 86, 43, and 22 GHz VLBI Observations of 3C120

20. Outburst in the Polarized Structure of the Compact Jet of 3C454.3

21. The twisted parsec-scale structure of 0735+178

22. Indication of a mass-dependent anisotropy above 10 18.7 eV in the hybrid data of the Pierre Auger Observatory

23. A tau scenario application to a search for upward-going showers with the Fluorescence Detector of the Pierre Auger Observatory

24. Study on multi-ELVES in the Pierre Auger Observatory

25. On the Location of the gamma-Ray Outburst Emission in the BL Lacertae Object AO 0235 + 164 Through Observations Across the Electromagnetic Spectrum

26. X-ray Dips Followed by Superluminal Ejections as Evidence for An Accretion Disc Feeding the Jet in A Radio Galaxy

27. Jet Stability and the Generation of Superluminal and Stationary Components

28. Upper limits to the detection of ammonia from protoplanetary disks around HL Tauri and L1551-IRS 5

29. A flattened cloud core in NGC 2024

30. A survey for water maser emission towards planetary nebulae. New detection in IRAS 17347-3139

31. Large-scale and multipolar anisotropies of cosmic rays detected at the Pierre Auger Observatory with energies above 4 EeV

32. Downward Terrestrial Gamma-ray Flashes at the Pierre Auger Observatory?

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32 results on '"Gomez, Jose A."'

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