Filters








183,250 Hits in 7.2 sec

Magnetic Fields in Irregular Galaxies

Krzysztof T. Chyży
2002 Highlights of Astronomy  
AbstractRadio data of large irregular galaxies reveal some extended synchrotron emission with a substantial degree of polarization.  ...  In the case of NGC 4449 strong galaxy-scale regular magnetic fields were found, in spite of the lack of ordered rotation required for the conventional dynamo action.  ...  In fact, IC 10 lacks clear signs of large-scale regular fields (Knapik et al., in prep). However, a polarized blob was detected, coincident with HI and CO peaks.  ... 
doi:10.1017/s1539299600014775 fatcat:2ruppj7wufgalgbs6c5uad7yay

Mesospheric plasma irregularities caused by the missile destruction on 9 December 2009

Alexander Kozlovsky, Sergey Shalimov, Mark Lester
2017 Journal of Geophysical Research - Space Physics  
The turbulence occurred at a height of about 80 km and was localized in several areas of about 60 km in horizontal scale.  ...  on the order of 0.1 s and a spatial scale of a few to tens of meters.  ...  Acknowledgments Data of the meteor radar are available from SGO (http://www.sgo.fi/). S.S. acknowledges support from the Academy of Finland grant 287916.  ... 
doi:10.1002/2017ja024300 fatcat:vr2q6hxj2rhrxjy3yh6lymqaym

Features of highly structured equatorial plasma irregularities deduced from CHAMP observations

C. Xiong, H. Lühr, S. Y. Ma, C. Stolle, B. G. Fejer
2012 Annales Geophysicae  
Such a result is in accord with 3-D model simulations (Aveiro and Hysell, 2010). Small-scale EPB structures are observed by CHAMP when the irregularities reach apex heights of 800 km and more.  ...  We filtered the FGM data by using band-passes with four different cut-off periods to get the EPBs with different maximum spatial scale sizes in the meridional plane ranging from 76–608 km.  ...  We would like to thank the German Space Operations Center (GSOC) of the German Aerospace Center (DLR) for providing continuously and nearly 100 % of the raw telemetry data of the CHAMP and GRACE satellites  ... 
doi:10.5194/angeo-30-1259-2012 fatcat:z2jkjmpq3jd77c4uqxkezspbnm

Onset conditions for equatorial spreadFdetermined during EQUIS II

D. L. Hysell, M. F. Larsen, C. M. Swenson, A. Barjatya, T. F. Wheeler, M. F. Sarango, R. F. Woodman, J. L. Chau
2005 Geophysical Research Letters  
The authors are indebted to the staffs of the Reagan Test Site on Kwajalein and of the Wallops Flight Facility who made this campaign possible and also to Erhan Kudeki and Robert Pfaff for many valuable  ...  The transient response of the instability could therefore account for the decakilometric large-scale waves in the postsunset ionosphere and that the steady-state response could account for the large scale  ...  We attribute this as well as the kinks in plasma density to the large-scale wave forming in the region and the emergence of ESF. [12] Downleg data for the second instrumented rocket flight appear in Figure  ... 
doi:10.1029/2005gl024743 fatcat:7vgzf75qprbjvlnktehj6kxeeq

Concurrent observations at the magnetic equator of small-scale irregularities and large-scale depletions associated with equatorial spread F

Dustin A. Hickey, Carlos R. Martinis, Fabiano S. Rodrigues, Roger H. Varney, Marco A. Milla, Michael J. Nicolls, Anja Strømme, Juan F. Arratia
2015 Journal of Geophysical Research - Space Physics  
The ASI measures airglow depletions associated with large-scale equatorial spread F irregularities (10s-100s km), while AMISR-14 detects small-scale irregularities (0.34 m).  ...  We compare data from the three instruments on the night of 20-21 August, 2014 by locating the radar scattering volume in the optical images.  ...  Acknowledgments This work was supported by grants from the Office of Naval Research for DURIP instrumentation at Jicamarca Observatory and data analysis funds from the NSF's Programs for Aeronomy 1123222  ... 
doi:10.1002/2015ja021991 fatcat:dcznhcqkmzgvzghwiopoccao4e

Anisotropy of small-scale stratospheric irregularities retrieved from scintillations of a double star α-Cru observed by GOMOS/ENVISAT

V. Kan, V. F. Sofieva, F. Dalaudier
2012 Atmospheric Measurement Techniques Discussions  
In this paper, we discuss estimating anisotropy of air density irregularities (ratio of characteristic horizontal and vertical scales) from satellite observations of bichromatic scintillations of a double  ...  The obtained estimates of the anisotropy coefficient correspond to small-scale irregularities, close to the buoyancy scale.  ...  The authors thank ESA, ACRI-ST and the GOMOS team for the GOMOS data. The work of V. Kan was supported by Russian Foundation for Basic Research, grant 12-05-00335. The work of V.  ... 
doi:10.5194/amtd-5-4881-2012 fatcat:uwzge64rhjh6fh5cprbwy65ak4

Anisotropy of small-scale stratospheric irregularities retrieved from scintillations of a double star α-Cru observed by GOMOS/ENVISAT

V. Kan, V. F. Sofieva, F. Dalaudier
2012 Atmospheric Measurement Techniques  
</strong> In this paper, we discuss estimating anisotropy of air density irregularities (ratio of characteristic horizontal and vertical scales) from satellite observations of bi-chromatic scintillations  ...  The obtained estimates of the anisotropy coefficient correspond to small-scale irregularities, close to the buoyancy scale.</p>  ...  The authors thank ESA, ACRI-ST and the GOMOS team for the GOMOS data. The work of V. Kan was supported by Russian Foundation for Basic Research, grant 12-05-00335. The work of V.  ... 
doi:10.5194/amt-5-2713-2012 fatcat:wr6sgtaktje7fahorq7n2m6wbm

Spatial and Temporal Distributions of Ionospheric Irregularities Derived from Regional and Global ROTI Maps

Chinh Thai Nguyen, Seun Temitope Oluwadare, Nhung Thi Le, Mahdi Alizadeh, Jens Wickert, Harald Schuh
2021 Remote Sensing  
The quantification of the degrees of disturbance reveals that about 58 times more ionospheric irregularities are observed in South America than in the southern mid-latitudes (least affected region).  ...  irregularities, which vary continuously in both time and space.  ...  Besides, to validate the results, we partly used the high-rate GNSS data provided by the Vietnam Academic of Science and Technology (VAST).  ... 
doi:10.3390/rs14010010 fatcat:3l7avhyxvjf55al27gpvidgwgm

Page 616 of Physical Review Vol. 50, Issue 7 [page]

1936 Physical Review  
Differences in actual filament area covered by the slit, if independent of other factors which are possible contributors to the structure, could be used to account fully for irregularities of the observed  ...  The com- putations show that dimensional irregularities necessary to account for the emission pattern are greater than any variations actually present in the wire.  ... 

The Smart Detection of Ship Severe Roll Motions and Decision-Making for Evasive Actions

Maria Acanfora, Flavio Balsamo
2020 Journal of Marine Science and Engineering  
This paper presents a numerical model for the smart detection of synchronous and parametric roll resonance of a ship.  ...  We conclude that, in roll resonance situations, and in the absence of roll stabilisation systems on-board, course change could be the most effective countermeasure.  ...  Conflicts of Interest: The authors declare no conflict of interest.  ... 
doi:10.3390/jmse8060415 fatcat:csxd6aefbvgx7f2rqrwk3tftqu

Distribution of star-forming complexes in dwarf irregular galaxies

B. R. Parodi, B. Binggeli
2003 Astronomy and Astrophysics  
We study the distribution of bright star-forming complexes in a homogeneous sample of 72 late-type ("irregular") dwarf galaxies located within the 10 Mpc volume.  ...  For the sample as a whole the radial number distribution of bright lumps largely traces the underlying exponential-disk light profiles, but peaks at a 10 percent smaller scale length.  ...  B.R.P. thanks Helmut Jerjen for introducing him to IRAF and for pointing out the HIPASS data release  ... 
doi:10.1051/0004-6361:20021587 fatcat:7dfc5nqmxne65p4pdlzi3b3lme

Activity as the Main Explanation of Light Variations of o And — Towards a Rotational Modulation Model

J.P. Sareyan, J. Chauville, M. Alvarez, G. Guerrero, A. Arellano Ferro, P. Mathias, J. Peña
2002 International Astronomical Union Colloquium  
The rest of the light variations do not show any permanent period or behavior, although a ∼ 2.3 d. (i.e. ≈ 3P1/2) period is frequently detected.  ...  by longer observations: our phase diagrams show significant irregular displacements around the average double-wave analytical solution if we include longer data strings (Fig. 1).  ...  Much of this work has received the continuous support of the CNRS, France and the CONACYT and UNAM, Mexico.  ... 
doi:10.1017/s0252921100016122 fatcat:vg3pzgkrqjgnpey3gq2x2vo55q

Page 23 of Astronomy and Astrophysics Vol. 230, Issue 1 [page]

1990 Astronomy and Astrophysics  
, because the difference between the smoothed outer-Galaxy rotation curve derived only from data at /< 180 and the one derived only from data at /> 180° is not large enough to account for the difference  ...  Fig. 7.10 in Burton, 1988b). The systematic differences in the velocity extents imply large-scale deviations from axial symmetry of either a spatial or kinematic nature.  ... 

Page 293 of Astronomy and Astrophysics Vol. 230, Issue 2 [page]

1990 Astronomy and Astrophysics  
one from the other to obtain a map that retains small-scale extended features, but eliminates the large-scale cluster emission.  ...  Reanalysis of two overlapping HRI observations of the cluster of galaxies A 1367 leads to the detection of an X-ray source identified with the peculiar/irregular galaxy Zw97-087 (UGC 6697).  ... 

Searching for Saturn's dust swarm: limits on the size distribution of irregular satellites from km to micron sizes

G. M. Kennedy, M. C. Wyatt, K. Y. L. Su, J. A. Stansberry
2011 Monthly notices of the Royal Astronomical Society  
Although we detected a degree scale Saturn-centric excess that might be attributed to an irregular satellite dust cloud, we attribute it to the far-field wings of the PSF due to nearby Saturn.  ...  The observations place an upper limit on the level of dust in the outer reaches of the Saturnian system, and constrain how the size distribution extrapolates from the smallest known (few km) size irregulars  ...  AC K N OW L E D G M E N T S This work is based in part on observations made with the Spitzer Space Telescope, which is operated by the Jet Propulsion Laboratory, California Institute of Technology under  ... 
doi:10.1111/j.1365-2966.2011.19409.x fatcat:ml2clo25lbdy7dblsz77fl3ox4
« Previous Showing results 1 — 15 out of 183,250 results