Related papers: A Frequency Comb calibrated Solar Atlas
Dual-comb spectroscopy is a promising method for precise optical spectrum analysis with fast data acquisition speed. However, its implementation and applications are often hindered by the complexity of optical comb systems. Here, as a…
We present a flux calibration scheme for the PACS chopped point-source photometry observing mode based on the photometry of five stellar standard sources. This mode was used for science observations only early in the mission. Later, it was…
The amplitudes of solar-like oscillations depend on the excitation and damping, both of which are controlled by convection. Comparing observations with theory should therefore improve our understanding of the underlying physics. However,…
The Sun is an extraordinary workbench, from which several fundamental astronomical parameters can be measured with high precision. Among these parameters, the solar radius $R_{\odot}$ plays an important role in several aspects, such as in…
We demonstrate dual-comb spectroscopy based on difference frequency generation of frequency-agile near-infrared frequency combs, produced with the help of electro-optic modulators. The combs have a remarkably flat intensity distribution and…
Chemical imaging enabled by Raman processes is crucial to investigating biological and chemical samples in a label-free manner. Stimulated Raman spectroscopy (SRS) overcomes the key limitation associated with low signal levels in…
Optical frequency comb synthesizers (FCs) [1] are laser sources covering a broad spectral range with a number of discrete, equally spaced and highly coherent frequency components, fully controlled through only two parameters: the frequency…
We present a new method for determining the location of active bands of latitude on solar-type stars, which uses stellar-cycle-induced frequency shifts of detectable solar-like oscillations. When near-surface activity is distributed in a…
Optimizing the photon spectrum for photosynthesis and improving crop yields presents an efficient pathway to alleviate global food shortages. Luminescent solar concentrators (LSCs), consisting of transparent host matrices doped with…
We calibrate spectrophotometric optical spectra of 32 stars commonly used as standard stars, referenced to 14 stars already on the HST-based CALSPEC flux system. Observations of CALSPEC and non-CALSPEC stars were obtained with the SuperNova…
We report a mode-locked Ti:sapphire femtosecond laser with 5GHz repetition rate. Spectral broadening of the 24 fs pulses in a microstructured fiber yields an octave-spanning spectrum and permits self-referencing and active stabilization of…
Context. Aalto University Mets\"ahovi Radio Observatory has collected solar intensity maps for over 45 years. Most data coverage is on the 37 GHz frequency band, tracking emissions primarily at the chromosphere and coronal transition…
The zero point of measured photospheric Doppler shifts is uncertain for at least two reasons: instrumental variations (from, e.g., thermal drifts), and the convective blueshift, a known correlation between intensity and upflows. Calibrated…
A multichannel dual-comb spectroscopy (DCS) approach for high-resolution, broadband spectral measurements is presented, demonstrating its effectiveness in studying complex atomic systems. By implementing a photodetector array, we enhance…
Context. Solar flux atlases observe the spatially integrated light from the Sun, treating it as a star. They are fundamental tools for gaining insight into the composition of the Sun and other stars, and are utilized as reference material…
With the rapid development of asteroseismology thanks to space-based photometry missions such as CoRoT, Kepler, TESS, and in the future, PLATO, and the use of inversion techniques, quasi-model-independent constraints on the stellar…
This paper presents the characterization of the optical range of the ALHAMBRA photometric system, a 20 contiguous, equal-width, medium-band CCD system with wavelength coverage from 3500A to 9700A. The photometric description of the system…
Optical frequency combs provide a phase-coherent interface between optical and microwave domains, underpinning advances in precision metrology, spectroscopy, and time-frequency transfer. Most conventional comb architectures are limited to…
We present results from a deep mid-infrared survey of the Hubble Deep Field South (HDF-S) region performed at 7 and 15 micron with the CAM instrument on board the Infrared Space Observatory (ISO). The final map in each band was constructed…
Metric and decametric radio-emissions from the Sun are the only direct source of information about the dynamics of non-thermal electrons in the upper corona. In addition, the combination of spectral and imaging (sizes, shapes, and…