Identify Emission Lines Research Articles

RADIATIVE L-SHELL TRANSITIONS IN Fe XIX AND Fe XX IONS

We compute the wavelengths and oscillator strengths for the 3s, 3d → 2p, and 3p → 2s emission lines in Fe XIX and Fe XX ions by using a configuration interaction Dirac-Fock and Dirac-Fock-Sturm method combined with second-order Brillouin-Wigner perturbation theory. We provide a complete list of computed wavelengths and oscillator strengths in both the velocity and length gauge for these transitions, many of which have never previously been reported. A comparison of our data with laboratory measurements and other theoretical predictions allows us to estimate an uncertainty of ~2 mA in the wavelengths and an uncertainty of 2%-3% in the oscillator strengths. We expect that our calculations will provide a means of identifying emission lines from astrophysical sources and improve the ability to detect blending in X-ray grating spectra from Chandra and XMM-Newton. As an example, we present a simulated emission spectrum of Capella and find improved agreement between the observations and our calculations, compared with previous data sets.

THE TEMPERATURE AND DENSITY STRUCTURE OF THE SOLAR CORONA. I. OBSERVATIONS OF THE QUIET SUN WITH THE EUV IMAGING SPECTROMETER ONHINODE

Measurements of the temperature and density structure of the solar corona provide critical constraints on theories of coronal heating. Unfortunately, the complexity of the solar atmosphere, observational uncertainties, and the limitations of current atomic calculations, particularly those for Fe, all conspire to make this task very difficult. A critical assessment of plasma diagnostics in the corona is essential to making progress on the coronal heating problem. In this paper, we present an analysis of temperature and density measurements above the limb in the quiet corona using new observations from the EUV Imaging Spectrometer (EIS) on Hinode. By comparing the Si and Fe emission observed with EIS we are able to identify emission lines that yield consistent emission measure distributions. With these data we find that the distribution of temperatures in the quiet corona above the limb is strongly peaked near 1 MK, consistent with previous studies. We also find, however, that there is a tail in the emission measure distribution that extends to higher temperatures. EIS density measurements from several density sensitive line ratios are found to be generally consistent with each other and with previous measurements in the quiet corona. Our analysis, however, also indicates that a significant fraction of the weaker emission lines observed in the EIS wavelength ranges cannot be understood with current atomic data.

Narrow-Band Microwave Radiation from a Biased Single-Cooper-Pair Transistor

We show that a single-Cooper-pair transistor (SCPT) electrometer emits narrow-band microwave radiation when biased in its subgap region. Photoexcitation of quasiparticle tunneling in a nearby SCPT is used to spectroscopically detect this radiation in a configuration that closely mimics a qubit-electrometer integrated circuit. We identify emission lines due to Josephson radiation and radiative transport processes in the electrometer and argue that a dissipative superconducting electrometer can severely disrupt the system it attempts to measure.

A high spectral resolution atlas and catalogue of emission lines of the comet C/2000 WM1 (LINEAR)

Using five high-resolution spectra of comet C/2000 WM1 (LINEAR) obtained on December 1 and 2, 2001 (UT) with the fiber fed extended range optical spectrograph (FEROS) installed on the 1.52-m reflector of the ESO (Chile, La Silla), we have constructed a high spectral resolution atlas and catalogue of cometary emission lines of this comet. Many emission lines of the molecules C 2, C 3, CN, CH, CH +, NH 2, CO +, H 2O +, and presumably CO and C 2 − were identified in the spectral range λλ 4000–9000 Å in the comet spectra. The total number of identified emission lines is 4537: C 2 – 2734, NH 2 – 1195, CN – 289, C 3 – 158, CO – 60, H 2O + – 51, CH – 50, CO + – 16, CH + – 8, C 2 − – 5. Also there are many unidentified emission lines in the comet spectrum.

Abundances of s-process elements in planetary nebulae: Br, Kr & Xe

We identify emission lines of post-iron peak elements in very high signal-to-noise spectra of a sample of planetary nebulae. Analysis of lines from ions of Kr and Xe reveals enhancements in most of the PNe, in agreement with theories of -process calculations indicate that it should be produced with Kr at detectable levels.

The identification of PM 1-322 as a new young high-density planetary nebulae

We report spectroscopic observations of a new planetary nebula PM 1-322, which has not yet been identified. This object was found during a northern survey of post-AGB and planetary nebulae candidates selected from Garcia-Lario et al. (1997, A&AS, 126, 479) and Preite-Martinez (1988, A&AS, 76, 317). Here we present the main spectroscopic features includ- ing a list of the intensities of the identified emission lines. The main spectral characteristic of PM 1-322 is the presence of a very strong (O ) λ4363 emission line (I(OIII)4363/Hβ � 120) indicating high electron densities (log Ne > 6.0). A comparison with similar objects strongly suggests that PM 1-322 is a very young planetary nebula, although the posibility of a symbiotic nature can not be ruled out.

Development of magnetic field mapping via heavy ion beam spectral imaging

Mapping magnetic fields via heavy ion beam spectral imaging relies upon establishing a high quality ion beam, identifying beam emission at wavelengths favorable for imaging, and designing an appropriate imaging configuration. Identifying emission lines suitable for imaging is difficult due to intense, broadband radiation of the target reversed field pinch plasma. To compensate, we have worked to raise the beam emission intensity. Simulations of the beam optics and characteristics have led to a technique that achieves a narrower beam and increased ion current at the plasma. Additionally, we are developing computer vision tools to reconstruct beam trajectories based on various camera and system configurations. We simulate charge coupled device images of the vessel interior and beam trajectories, and reconstruct three dimensional trajectories from image pairs. Analysis of the simulated images will guide the system specifications. We present results of the beam optics and camera simulations, surveys of radiation, and status of the diagnostic.

Laser-induced time-resolved luminescence of natural titanite CaTiOSiO4

Abstract The time-resolved laser-induced luminescence spectroscopy of natural titanite enables to detect and identify emission lines of trivalent rare-earth elements, such as Sm, Eu, Er, Pr, Tm, Nd, and transition elements, such as Cr 3+ in strong and intermediate crystal field sites. Energy migration between Cr 3+ site and Nd 3+ is detected.

The Caii–Mv Correlation (Wilson‐Bappu Effect) Calibrated by Hipparcos Parallaxes

ABSTRACTWe have used Hipparcos parallaxes to derive absolute visual magnitudes of G, K, and M stars with Ca ii emission line widths previously measured by O. C. Wilson. A linear relationship similar to the one derived originally by Wilson & Bappu and improved by Lutz & Kelker was found from Mv = +7 to −2. For stars brighter than Mv = -2 a substantial number of stars show Ca ii emission lines that are broader than expected from the linear fit. Most of those stars are bright giants and supergiants of type G. In appendices we show some sample Ca ii profiles and identify emission lines of Fe ii as well as the Hϵ line in some stars.

UV BRIGHT GALAXIES IN THE CASE LOW-DISPERSION NORTHERN SKY SURVEY

ABSTRACT Spectroscopy and CCD photometry have been obtained to investigate four galaxies reported to have unusually strong UV excess in their objective prism spectra. The spectra of CG 1293 (B152299+302942) and CG 1331 (B155442+295724) suggest they are Seyfert 1 galaxies, with z = 0.1260±0.0002 (standard error) and z = 0.0874±0.0009, respectively. Hα in CG 1293 has a line width (FWHM) of approximately 4 x 103 km s-1. The Hα, Hβ, and Hγ lines in CG 1331 have line widths greater than 7 x 103 km s-1. Spectra for the galaxies CG 1280 (B150126+300206) and CG 1298 (B153025+315554) have no identified emission lines. We find MB=-22.13 for CG 1293 and MB=-22 for CG 1331, for H0=50 km s-1 Mpc-1 and q0=0.5.

Fe II and Fe i Emission in IRAS 07598+6508 and PHL 1092

view Abstract Citations (32) References (21) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Fe II and Fe i Emission in IRAS 07598+6508 and PHL 1092 Kwan, John ; Cheng, Fu-Zhen ; Fang, Li-Zhi ; Zheng, Wei ; Ge, Jian Abstract We have obtained high S/N spectra for two Fe II-strong quasars, IRAS 07598+6508 and PHL 1092. In addition to Fe II features, we have identified emission lines of Fe I and Ti II. We believe the energy source for the line emission is heat and propose an idea in which an accretion disk may produce the observed emission. Publication: The Astrophysical Journal Pub Date: February 1995 DOI: 10.1086/175302 arXiv: arXiv:astro-ph/9409095 Bibcode: 1995ApJ...440..628K Keywords: Astrophysics E-Print: 17 pages, Latex, figures available upon request, to appear in ApJ full text sources arXiv | ADS | data products SIMBAD (2) NED (2)

The subluminous, spectroscopically peculiar type IA supernova 1991bg in the elliptical galaxy NGC 4374

We present photometric and spectroscopic observations of SN 1991bg, a very peculiar Type Ia supernova located in the outskirts of the E1 galaxy NGC 4374 (M84) in the Virgo cluster. At maximum brightness SN 1991bg was 1.6 mag subluminous in V and 2.5 mag subluminous in B, compared with normal SNe Ia. The colors were unusually red, but the object was not significantly reddened by dust. The decline from maximum was certainly quite steep; we measure an initial linear V fading of 0.10 mag d^-1^ rather than the typical value of 0.06 mag d^-1^ for SNe Ia, and a late- time decline of 0.034 mag d^-1^ rather than 0.026 mag d^-1^. Furthermore, the knee in the Flight curve of SN 1991bg occurs only ~17 d past B maximum, in contrast to the usual value of 30-40 d. Unlike normal SNe Ia, the I light curve does not exhibit a secondary maximum, and the R light curve shows no sign of a plateau. Despite having prominent Si II absorption near 6150 A, characteristic of SNe Ia, SN 1991bg was spectroscopically peculiar at maximum brightness; e.g. a deep trough was present around 4200 A. Spectral synthesis suggests that much of this feature was produced by Ti II. Indeed, Ti II was present elsewhere in the spectrum whereas Fe II was weak or absent. Lines due to other intermediate-mass elements were also strong near maximum brightness, but the expansion velocity (~10 000 km s^-1^) was slightly lower than average (11 000-13 000 km s^-1^) for SNe Ia. A spectrum obtained 3 weeks past maximum has a rather narrow absorption line attributed to Na I D; the strength of this feature grew with time. In certain other respects the spectrum 3 weeks past maximum more closely resembles spectra of SNe Ib/Ic than of SNe Ia. We identify emission lines of [Ca II] λλ7291, 7324, O I λ7773, the Ca II infrared triplet, and (tentatively) [O I] λ5577, all superimposed on a complex blend of P Cygni scattering lines; apparently the nebular phase began very early in SN 1991bg. Three months past maximum the [Ca II] blend started to dominate the spectrum. The properties of SN 1991bg suggest that this object was produced by the slow deflagration of a white dwarf. The observed expansion velocity, however, is too large unless a sub-Chandrasekhar mass of material was ejected. An unusually low mass for the ejecta expanding at a nearly normal velocity, is consistent with the early transition to the nebular phase as well as with the rapid decline and the early knee in the V light curve. Thus, SN 1991bg may have resulted from the deflagration of only the outer layer of material on top of a C-O core, thereby leaving a compact remnant; alternatively, perhaps the complete explosion of a low-mass (~1.0 M_sun_) white dwarf was responsible. We show that some properties of the peculiar SN 1986G in Cen A were similar to those of SN 1991bg, and it may have been intrinsically dim by several magnitudes. Moreover, SN 1971I in NGC 5055 is known to have resembled SN 1986G; thus, SN 1991bg was probably a close cousin of these two objects. SN 1991bg clearly demonstrates that at least some SNe 1a are mavericks, both photometrically and spectroscopically. These objects must be carefully eliminated from samples of SNe 1a used in determinations of cosmological parameters.

MRSP - The Muenster Redshift Project

ESO/SRC-J-Atlas plates (film copies) and film copies of UK-Schmidt objective prism J-plates (dispersion 246nm/mm at Hγ) were scanned with the microdensitometer PDS 2020 GM and reduced automatically with the software package ADAS developed at the Astronomical Institute of Muenster University. In a single field (30 square degrees) near the South Galactic Pole 150 000 objects are found up to the limiting magnitude Stars and galaxies are separated. Algorithms for quasar search among the star-like objects are applied and radial velocities determined from the identified emission lines. Follow-up observations with the ESO 3.6m telescope show fair agreement between the redshifts determined from the objective prism plate and from the slit spectra.

Spatial structure in lines in the 3398?3526 � region at the extreme limb: Observation, identification and interpretation

We have obtained spectrograms of high spatial and spectral resolution of the extreme solar limb, using the vacuum tower telescope of Sacramento Peak Observatory. We have identified emission lines in the range 3398–3526 A, and classified them according to intensity, spatial structure (intensity variation), and profile. Some lines show spatial intensity variation; others do not. We show that this effect is related to the abundance of the element responsible for the line and the mean lower-level excitation potential of interlocked lines. We explain the effect in terms of radiative interlocking with other lines, as well as the characteristic size of the volume contributing to the mean intensity.