Search Publications
Star formation history in the central region of the barred galaxy NGC 7177
Sil'Chenko, O. K.; Smirnova, A. A.
Using the method of two-dimensional spectroscopy, we have investigated the kinematics and distribution of the gas and stars at the center of the early-type spiral galaxy NGC 7177 with a mediumscale bar as well as the change in the mean age of the stellar population along the radius. A classical picture of radial gas inflow to the galactic center a…
Hot Gas in the Galactic Thick Disk and Halo Near the Draco Cloud
Shelton, R. L.; Henley, D. B.; Dixon, W. V.
This paper examines the ultraviolet and X-ray photons generated by hot gas in the Galactic thick disk or halo in the Draco region of the northern hemisphere. Our analysis uses the intensities from four ions, C IV, O VI, O VII, and O VIII, sampling temperatures of ~105 to ~3 × 106 K. We measured the O VI, O VII, and O VIII int…
Corrigendum to "Substorm activity in Venus's magnetotail" published in Ann. Geophys., 27, 2321-2330, doi:10.5194/angeo-27-2321-2009, 2009
Barabash, S.; Futaana, Y.; Zhang, T. L. +5 more
A re-evaluation of the reconnection event reported by Volwerk et al. (2009) shows that the original interpretation of the magnetic field data as quadrupolar Hall-current signatures around a reconnection site was mistaken. It could be interpreted as the signature of reconnection in the presence of a guide field. The path of VEX through the active r…
101 Minima Times of Eclipsing Binaries Observed by INTEGRAL/OMC
Zasche, P.
The INTEGRAL/OMC CCD minima observations of eclipsing binaries are presented.
A Search for RR Lyrae Variables in the Central Region of M54
Mighell, Kenneth J.; Montiel, Edward J.
We have analyzed archival Hubble Space Telescope (HST) Wide Field Planetary Camera 2 (WFPC2) observations of the central region of the globular cluster M54. The 12 irregularly timed observations (6 F555W, 6 F814W) were reduced using the HSTphot stellar photometry package. Our statistical analysis of the HSTphot photometry yielded 50 variable stars…
A morphological study of CMEs using wavelet analysis
Raga, A. C.; Blanco-Cano, X.; González-Gómez, D. I.
The principal objective of this study is to analyze structures of Coronal Mass Ejections (CMEs) using a wavelet technique. We use data measured with the SOHO/LASCO coronographs C2-C3, EIT and STEREO COR1A-B, COR2A-B. We have found that different structures show up in a CME at different spatial scales of wavelets. We also study the orientation of t…
Review of Hinode results
Suematsu, Y.
Hinode is an observatory-style satellite, carrying three advanced instruments being designed and built to work together to explore the physical coupling between the photosphere and the upper layers for understanding the mechanism of dynamics and heating. The three instruments aboard are the Solar Optical Telescope (SOT), which can provide high-pre…
Seeing-Induced Errors in Solar Doppler Velocity Measurements
Sridharan, R.; Sankarasubramanian, K.; Padinhatteeri, Sreejith
Imaging systems based on a narrow-band tunable filter are used to obtain Doppler velocity maps of solar features. These velocity maps are created by taking the difference between the blue- and red-wing intensity images of a chosen spectral line. This method has the inherent assumption that these two images are obtained under identical conditions. …
Advances in solar rotation rate inferences: Unstructured grid inversions and improved rotational splittings
Eff-Darwich, A.; Korzennik, S. G.; García, R. A.
We present a new inversion methodology that adapts the inversion grid in both radius and co-latitude to the data set and solves the inversion problem through an iterative procedure. This method was tested on state-of-the-art global mode frequency splittings to assess the solar interior rotation rate and its temporal variation. We also explore the …
Frequency-resolved spectroscopy of XB1323-619 using XMM-Newton data: detection of a reflection region in the disc
Balman, Ş.
We present the frequency-resolved energy spectra (FRS) of the low-mass X-ray binary dipper XB1323-619 during persistent emission in four different frequency bands using an archival XMM-Newton observation. FRS method helps to probe the inner zones of an accretion disc. XB1323-619 is an Atoll source and a type-I burster. We find that the FRS is well…