相关论文: Multi-segment and Echelle stellar spectra processi…
We investigate the star formation and dust extinction properties of very luminous infrared galaxies whose spectra display a strong Hdelta line in absorption and a moderate [OII] emission (e[a] spectrum). This spectral combination has been…
Libraries of stellar spectra are fundamental tools in the study of stellar populations and in automatic determination of atmospheric parameters for large samples of observed stars. In the context of the present volume, here I give an…
Using the NIRSPEC spectrograph at Keck II, we have obtained echelle spectra covering the range 1.5-1.8um for 2 of the brightest giants in Liller 1 and NGC 6553, old metal rich globular clusters in the Galactic bulge. We use spectrum…
Dust attenuation shapes the spectral energy distribution of galaxies. It is particularly true for dusty galaxies in which stars experience a heavy attenuation. The combination of UV-to-IR photometry with the spectroscopic measurement of the…
With the availability of multi-object spectrometers and the designing \& running of some large scale sky surveys, we are obtaining massive spectra. Therefore, it becomes more and more important to deal with the massive spectral data…
We present an analysis of the integrated properties of the stellar populations in the Universidad Complutense de Madrid Survey of Halpha-selected galaxies. In this paper, the first of a series, we describe in detail the techniques developed…
Models of population synthesis for the Galaxy have been developed in order to understand galactic structure and evolution. They allow to test scenarii of evolution by comparisons between model predictions and observed distributions.…
We introduce crowded field integral field (3D) spectrophotometry as a useful technique for the study of resolved stellar populations in nearby galaxies. As a methodological test, we present a pilot study with selected extragalactic…
The accurate measurement of stellar masses over a wide range of galaxy properties is essential for better constraining models of galaxy evolution. Emission line galaxies (ELGs) tend to have better redshift estimates than continuum-selected…
The CHIRON optical high-resolution echelle spectrometer was commissioned at the 1.5m telescope at CTIO in 2011. The instrument was designed for high throughput and stability, with the goal of monitoring radial velocities of bright stars…
Integrated light from distant galaxies is often compared to stellar population models via the equivalent widths of spectral features--spectral indices--whose strengths rely on the abundances of one or more elements. Such comparisons hinge…
Spectral clustering methods have gained widespread recognition for their effectiveness in clustering high-dimensional data. Among these techniques, constrained spectral clustering has emerged as a prominent approach, demonstrating enhanced…
The spectrophotometric flux calibration of recent spectroscopic surveys has reached a limiting systematic precision of approximately 1-3 percent, and is often biased near the wavelengths associated with H I Balmer absorption. As we prepare…
We describe a possible new technique for precise wavelength calibration of high-resolution astronomical spectrographs using femtosecond-pulsed mode-locked lasers controlled by stable oscillators such as atomic clocks. Such `frequency combs'…
Estimating accurate bolometric fluxes for stars requires reliable photometry to absolutely flux calibrate the spectra. This is a significant problem for studies of very bright stars, which are generally saturated in modern photometric…
The light emitted from the stellar photosphere serves as a unique signature for the nature of stars. The behaviour of these stellar lines depend upon the surface temperature, mass, evolutionary status and chemical composition of the star.…
Multi-wavelength spectroscopy can be used to constrain the dust and gas properties in debris disks. Circumstellar dust absorbs and scatters incident stellar light. The scattered light is sometimes resolved spatially at visual and…
The SDSS-III/APOGEE survey operated from 2011-2014 using the APOGEE spectrograph, which collects high-resolution (R~22,500), near-IR (1.51-1.70 microns) spectra with a multiplexing (300 fiber-fed objects) capability. We describe the survey…
In this paper, we present a deep learning system approach to estimating luminosity, effective temperature, and surface gravity of O-type stars using the optical region of the stellar spectra. In previous work, we compare a set of machine…
New instrumental capabilities and the wealth of astrophysical information extractable from the near-infrared wavelength region have led to a growing interest in the field of high resolution spectroscopy at 1-5 mu. We aim to provide a…