A5028823405- Astrophysics and Star Formation Studies
- Stellar, planetary, and galactic studies
- Galaxies: Formation, Evolution, Phenomena
- Atmospheric Ozone and Climate
- Astro and Planetary Science
- Astronomical Observations and Instrumentation
- Astronomy and Astrophysical Research
- Spectroscopy and Laser Applications
- Molecular Spectroscopy and Structure
- Calibration and Measurement Techniques
- Astrophysical Phenomena and Observations
- Atomic and Molecular Physics
- Gamma-ray bursts and supernovae
- Spectroscopy Techniques in Biomedical and Chemical Research
- Molecular spectroscopy and chirality
- Planetary Science and Exploration
- Impact of Light on Environment and Health
- Historical Astronomy and Related Studies
- Light effects on plants
- Solar and Space Plasma Dynamics
- Medical and Biological Sciences
- Bee Products Chemical Analysis
- Adaptive optics and wavefront sensing
- Advanced Chemical Physics Studies
- Astrophysics and Cosmic Phenomena
University of Helsinki
2006-2023
Finnish Geospatial Research Institute
2016-2023
University of Jyväskylä
2022
Max Planck Institute for Astronomy
2018
Max Planck Society
2018
Helsinki Institute of Physics
2012
We report observations of the southern Bok globule BHR 71 in J = 1 → 0 and 2 lines 12CO, 13CO C18O, (J, K) (1, 1) (2, 2) inversion NH3 made with angular resolution ~20'' to ~9'. also 1.3 mm continuum SEST resolution. The low molecular indicate that has a diameter ~0.5 pc, kinetic temperature 11 K, total mass ~40 M☉, an average density ~9 × 103 cm-3. high reveal presence, near center globule, highly collimated bipolar outflow lobes extending by ~0.3 pc opposite directions from strong source....
<i>Context. <i/> We present the first results from project Galactic cold cores, where interstellar clouds detected by <i>Planck<i/> satellite are studied with <i>Herschel<i/> photometric observations. The final catalogue is expected to contain several thousand sources. observations during science demonstration phase provided glimpse into nature of these sources.<i>Aims. <i/>The main goal derive physical properties core population revealed <i>Planck<i/>. examine three fields and confirm...
We have conducted a survey of SiO emission towards galactic H2O and OH masers ultracompact HII regions using the 15-m SEST 20-m Onsala telescope. With transitions (, ) (,) at 3 2 mm were measured simultaneously. only line was accessible. Altogether 369 objects observed detected 137 them. The detection rate is highest most intense masers, which probably require powerful shocks to be excited. correlates also with integrated far-infrared flux density FIR luminosity associated IRAS point source,...
In a project aimed at measuring the optical Extragalactic Background Light (EBL) we are using shadow of dark cloud.We have performed, with ESO VLT/FORS, spectrophotometry surface brightness towards high-galactic-latitude cloud Lynds 1642. A spectrum representing difference between opaque core and several unobscured positions around was presented in Paper I (Mattila et al. 2017a). The topic present paper is separation scattered starlight from itself which only remaining foreground component...
Phytochromes are photoreceptors sensitive to red and far light found in a wide variety of organisms, including plants, fungi, bacteria. Bacteriophytochromes (BphPs) can be switched between Pr state light-sensitive Pfr by illumination. In so-called prototypical BphPs, the functions as thermally favoured resting state, whereas is more stable bathy BphPs. The Dr BphP from Deinococcus radiodurans has been shown compatible with different output module types. Even though regulated optogenetic...
We report observations of the J = 3 → 2 and 1 transitions SiO CS, Jk 3k 2k 1k CH3OH, 0 transition HCO+, made with Swedish-ESO Submillimetre Telescope (SEST), toward highly collimated bipolar outflow BHR 71. Broad wing emission was detected lobes in all observed molecular lines. The shapes profiles are strikingly different from molecule to molecule. For CS HCO+ outflowing gas appears as a weak broad feature superposed upon strong narrow quiescent ambient gas. CH3OH intensity is considerably...
We have mapped the dark cloud L183 in far-infrared at 100 μm and 200 with ISOPHOT photometer aboard ISO satellite. The observations make it possible for first time to study distribution properties of large dust grains without confusion from smaller grains. show clear colour temperature variations which are likely be caused by changes emission particles. In core drops below 12 K. data allow a new determination mass based on emission. estimated within radius 10′ centre is 25 . several...
We investigate the relationship between C18O column density and visual extinction in Chamaeleon I a part of III molecular cloud. The densities, N(C18O), are calculated from rotational line data observed with SEST telescope. extinctions, , derived using photometry 2MASS survey NICER color excess technique. In contrast previous results Hayakawa et al. (2001, PASJ, 53, 1109), we find that average N(C18O) ratios similar Cha III, lie close to values for other clouds, i.e. . find, however, clear...
We have analyzed the properties of dust in high galactic latitude translucent cloud Lynds 1780 using ISOPHOT maps at 100 μm and 200 raster scans 60 μm, 80 120 150 μm. In far-infrared (FIR) emission, has a single core that coincides with maxima visual extinction optical depth. At resolution 3.0′, maximum is 4.0 mag. core, minimum temperature depth are 14.9 ± 0.4 K 2.0 0.2 10-3, respectively, 1.5′. The mass estimated to be 18 . FIR observations, combined IRAS suggest presence different,...
We have studied the ratio of 13CO and C18O column densities to extinction AJ background field stars in direction three globules: B 133, 335, L 466. Selected positions globules were observed 12CO() line transitions using 15-m Swedish-ESO Submillimetre Telescope (SEST) Chile. One clouds, 466, was also mapped C18O() line. In addition N(13CO)/AJ N(C18O)/AJ ratios N(13CO) N(C18O) AV N(H2) are given. These found vary from cloud so that they larger 335 than 133 variations thought primarily arise...
Bright emission nebulae, or H II regions, around hot stars are readily seen in Hα light. However, the all-pervasive faint has only recently been detected and mapped over whole sky. Mostly observed along a line of sight is produced by ionized gas situ. There are, however, cases where all most radiation due to scattering electrons dust particles that illuminated an Hα-emitting source off sight. Here we demonstrate diffuse, translucent, dark clouds at high Galactic latitudes many have excess...
Aims.The purpose of this study is to examine the prediction that deuterated H ion, H2D+, can be found exclusively in coldest regions molecular cloud cores. This also a feasibility for detection ground-state line ortho-H2D+ at 372 GHz with APEX.
Context. Cold cores in interstellar molecular clouds represent the very first phase star formation. The physical conditions of these objects are studied order to understand how evolve and stellar masses determined.
We present a set of 6–12 ISOPHOT-S spectra the general interstellar medium Milky Way. This part spectrum is dominated by series strong, wide emission features commonly called Unidentified Infrared Bands. The sampled area covers inner Way from l = -60°to +60° with ten-degree step in longitude and nominal latitudes b 0°, ±1°. For each grid position actual observed direction was selected IRAS 100 maps to minimize contamination point sources molecular clouds. All were found display same spectral...
The Cederblad 110 reflection nebula contains several young stellar objects previously discovered by IRAS and sub-mm observations. This cluster was revisited with ISO's FIR cameras mapped higher spatial resolution. All sources were also for the first time near maximum of their spectral energy distribution at 200 μm. In addition, two new FIR-sources discovered. data enabled parameters to be determined, such as luminosity, temperature mass circumstellar dust. These related YSO classes various...
Our aim is to compare the infrared properties of big, ``classical'' dust grains with visual extinction in cloud L1642. In particular, we study differences grain emissivity between diffuse and dense regions cloud. The far-infrared are based on large-scale 100um 200um maps. Extinction through has been derived by using star count method at B- I-bands, color excess J, H Ks bands. Radiative transfer calculations have used effects increasing absorption cross-section emission temperature. Dust...
We have performed a large-scale mapping of the high-latitude, moderate extinction dark cloud L 1642 with ISO (Infrared Space Observatory) at 200 μm to study properties dust, virial equilibrium condition cloud, and their relation star formation. The consists three denser regions which are connected by diffuse material. Only one regions, most massive greatest optical depth, is related temperature mimimum. pre-main sequence binary stars IRAS 04325-1419 04327-1419, probably born within located...
Abstract The Extragalactic Background Light (EBL) at UV, optical and NIR wavelengths consists of the integrated light all unresolved galaxies along line sight plus any contributions by intergalactic matter including hypothetical decaying relic particles. measurement EBL has turned out to be a tedious problem. This is because foreground components night sky brightness, much larger than itself: Zodiacal (ZL), Integrated Starlight (ISL), Diffuse Galactic (DGL) and, for ground-based...
Context. The Carte du Ciel archive at the University of Helsinki enables us to see sky as it was about 120 yr ago. consists single-exposure and triple-exposure plates between epochs 1896.8–1925.8. Aims. Our main aim is find binary multiple stars by combining Gaia data. Methods. were digitised with a commercial digital camera. We used data calculate predicted coordinates epoch each plate. These reference fit astrometry for plate, giving fitted on plates. If differed significant level, we...
We present the method and observations for measurement of Extragalactic Background Light (EBL) utilizing shadowing effect a dark cloud. measure surface brightness difference between opaque cloud core its unobscured surroundings. In large atmospheric Zodiacal light components are eliminated only remaining foreground component is scattered starlight from itself. Although much smaller, separation key problem in method. For we use spectroscopy. While has characteristic Fraunhofer lines 400 nm...