Marko Gacesa

Panchromatic properties of 99 000 galaxies detected by SDSS, and (some by) ROSAT, GALEX, 2MASS, IRAS, GB6, FIRST, NVSS and WENSS surveys

We discuss the panchromatic properties of 99,088 galaxies selected from the Sloan Digital Sky Survey Data Release 1 “main” spectroscopic sample (a flux-limited sample for 1360 deg 2 ). These galaxies are positionally matched to sources detected by ROSAT, GALEX, 2MASS, IRAS, GB6, FIRST, NVSS and WENSS. The matching fraction varies from < 1% for ROSAT and GB6 to �40% for GALEX and 2MASS. In addition to its size, the advantages of this sample are well controlled selection effects, faint flux limits and the wealth of measured parameters, including accurate X-ray to radio photometry, angular sizes, and optical spectra. We find strong correlations between the detection fraction at other wavelengths and optical properties such as flux, colors, and emission-line strengths. For example, �2/3 of SDSS “main” galaxies classified as AGN using emission-line strengths are detected by 2MASS, while the corresponding fraction for star-forming galaxies is only �1/10. Similarly, over 90% of galaxies detected by IRAS display strong emission lines in their optical spectra, compared to �50% for the whole SDSS sample. Using GALEX, SDSS, and 2MASS data, we construct the UV-IR broad-band spectral energy distributions for various types of galaxies, and find that they form a nearly one-parameter family. For example, the SDSS u- and r- band data, supplemented with redshift, can be used to “predict” K-band magnitudes measured by 2MASS with an rms scatter of only 0.2 mag. When a dust content estimate determined from SDSS spectra with the aid of models is also utilized, this scatter decreases to 0.1 mag and can be fully accounted for by measurement uncertainties. We demonstrate that this interstellar dust content, inferred from optical SDSS spectra by Kauffmann et al. (2003a), is indeed higher for galaxies detected by IRAS and that it can be used to “predict” measured IRAS 60 µm flux density within a factor of two using only SDSS data. We also show that the position of a galaxy in the emission-line-based Baldwin-Phillips-Terlevich diagram is correlated with the optical light concentration index and u r color determined from the SDSS broad-band imaging data, and discuss changes in the morphology of this diagram induced by requiring detections at other wavelengths. Notably, we find that SDSS “main” galaxies detected by GALEX include a non-negligible fraction (10-30%) of AGNs, and hence do not represent a clean sample of starburst galaxies. We study the IR-radio correlation and find evidence that its slope

Efficient formation of ground-state ultracold molecules via STIRAP from the continuum at a Feshbach resonance

We develop a theoretical description of photoassociative stimulated Raman adiabatic passage (STIRAP) near a Feshbach resonance in a thermal atomic gas. We show that it is possible to use low-intensity laser pulses to directly excite pairs of atoms in the continuum near a Feshbach resonance and to transfer most of the atomic cloud to the lowest rovibrational level of the molecular ground state. For a broad resonance, commonly found in several mixtures of alkali atoms, our model predicts a transfer efficiency up to 97% for a given atom pair, and up to 70% when averaged over an atomic ensemble. The laser intensities and pulse durations needed for such an optimal transfer, 102–103 W cm−2 and several microseconds, are easily achievable experimentally. A single pair of STIRAP pulses converts an estimated fraction f~10−6–10−4 of atoms in an atomic ensemble, leading to the production of 10–1000 molecules in a large sample of 107 atoms. A total of ~104–106 pulse pairs are thus required to transfer most atoms into molecules. Such an efficiency compares with or surpasses currently available techniques for creating stable diatomic molecules, and the versatility of this approach simplifies its potential use for many molecular species.

Non‐thermal escape of molecular hydrogen from Mars

We present a detailed theoretical analysis of a non-thermal escape of molecular hydrogen from Mars induced by collisions with hot atomic oxygen from martian corona. To accurately describe the energy transfer in O + H

Feshbach resonances in ultracold 6'7Li+23Na atomic mixtures

_2(v,j)

Phase gate and readout with an atom-molecule hybrid platform

collisions, we performed extensive quantum-mechanical calculations of state-to-state elastic, inelastic, and reactive cross sections. The escape flux of H

Production ofNaCa+molecular ions in the ground state from cold atom-ion mixtures by photoassociation via an intermediate state

_2

Photoassociation of ultracold molecules near a Feshbach resonance as a probe of the electron–proton mass ratio variation

molecules was evaluated using a simplified 1D column model of the martian atmosphere with realistic densities of atmospheric gases and hot oxygen production rates for the low solar activity conditions. An average density of the non-thermal escape flux of H

Feshbach-optimized photoassociation of ultracold

_2

^6

of

Li

1.9\times10^5