A5042669809- Astrophysics and Star Formation Studies
- Galaxies: Formation, Evolution, Phenomena
- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Molecular Spectroscopy and Structure
- Atmospheric Ozone and Climate
- Radio Astronomy Observations and Technology
- Astrophysics and Cosmic Phenomena
- Astronomical Observations and Instrumentation
- Spectroscopy and Laser Applications
- Gamma-ray bursts and supernovae
- Calibration and Measurement Techniques
- Astro and Planetary Science
- Advanced Combustion Engine Technologies
- Astrophysical Phenomena and Observations
- Research in Social Sciences
- Advanced Chemical Physics Studies
- Plant Genetic and Mutation Studies
- Aquatic life and conservation
- Avian ecology and behavior
- Neutrino Physics Research
Council of State
2024
Research Council of Finland
2020-2022
University of Zagreb
2015-2017
University of Helsinki
2006-2017
Helsinki Institute of Physics
2013
Turku Centre for Computer Science
2010
University of Turku
2010
We present the VLA-COSMOS 3 GHz Large Project based on 384 hours of observations with Karl G. Jansky Very Array (VLA) at (10 cm) toward two square degree Cosmic Evolution Survey (COSMOS) field. The final mosaic reaches a median rms 2.3 uJy/beam over degrees an angular resolution 0.75". To fully account for spectral shape and variations across broad (2 GHz) band, we image all data multiscale, multifrequency synthesis algorithm. catalog 10,830 radio sources down to 5 sigma, out which 67 are...
We make use of the deep Karl G. Jansky Very Large Array (VLA) COSMOS radio observations at 3 GHz to infer luminosity functions star-forming galaxies up redshifts z~5 based on approximately 6000 detections with reliable optical counterparts. This is currently largest radio-selected sample available out across an area 2 square degrees a sensitivity rms=2.3 ujy/beam. By fixing faint and bright end shape function local values, we find strong redshift trend that can be fitted pure evolution...
We determine the physical properties of a sample SMGs in COSMOS field that were pre-selected at observed wavelength $λ_{\rm obs}=1.1$ mm, and followed up obs}=1.3$ mm with ALMA. used MAGPHYS to fit panchromatic (ultraviolet radio) SEDs 124 target SMGs, 19.4% which are spectroscopically confirmed. The SED analysis was complemented by estimating gas masses using emission as tracer molecular gas. median 16th-84th percentile ranges stellar masses, SFRs, dust temperatures, derived be...
We explore the multiwavelength properties of AGN host galaxies for different classes radio-selected out to z$\lesssim$6 via a analysis about 7700 radio sources in COSMOS field. The were selected with Very Large Array (VLA) at 3 GHz (10 cm) within VLA-COSMOS Project, and cross-matched ancillary data. This is largest sample high-redshift (z$\lesssim$6) exquisite photometric coverage redshift measurements available. constructed moderate-to-high radiative luminosity (HLAGN) spectral energy...
We study the physical properties of a sample 6 SMGs in COSMOS field, spectroscopically confirmed to lie at z>4. use new GMRT 325 MHz and 3 GHz JVLA data probe rest-frame 1.4 emission z=4, estimate sizes star-forming (SF) regions these sources, resp. Combining our size estimates with those available literature for AzTEC1 AzTEC3 we infer median radio-emitting z>4 (0.63"+/-0.12")x(0.35"+/-0.05") or 4.1x2.3 kpc^2 (major times minor axis; assuming z=4.5) lower if take two marginally resolved as...
We carried out targeted ALMA observations of 129 fields in the COSMOS region at 1.25 mm, detecting 152 galaxies S/N$\geq$5 with an average continuum RMS 150 $\mu$Jy. These represent a S/N-limited sample AzTEC / ASTE sources 1.1 mm S/N$\geq$4 over area 0.72 square degrees. Given ALMA's fine resolution and exceptional spectroscopic multiwavelength photometric data available COSMOS, this survey allows us unprecedented power identifying submillimeter galaxy counterparts determining their...
We used the PdBI to map a sample of 15 SMGs in COSMOS field at wavelength 1.3 mm. The target were originally discovered JCMT/AzTEC 1.1 mm continuum survey S/N=4-4.5. This paper presents, for first time, interferometric millimetre-wavelength observations these sources. angular resolution our observations, 1.8", allowed us accurately determine positions SMGs. Using detection threshold S/N>4.5 regardless multiwavelength counterpart association, and 4<S/N<=4.5 if within 1.5" is also present,...
We study the environment of 23 submillimetre galaxies (SMGs) drawn from JCMT/AzTEC 1.1mm S/N-limited sample in COSMOS field, as well 4 SMGs at z_spec>4.5, and 1 z_spec=2.49, yielding a 28 SMGs. search for overdensities using photometric redshifts based on over 30 UV-NIR bands, reaching an accuracy sigma(Delta z/(1+z))=0.0067 (0.0155) z<3.5 (>3.5). To identify we apply Voronoi tessellation analysis, estimate overdensity estimator delta_g function distance SMG and/or center. test validate our...
We aim to further constrain the properties and evolutionary stages of dense cores in Orion B9. The central part B9 was mapped at 350 micron with APEX/SABOCA. A sample nine region were observed C17O(2-1), H13CO+(4-3) (towards 3 sources), DCO+(4-3), N2H+(3-2), N2D+(3-2) APEX/SHFI. These data are used conjunction our previous APEX/LABOCA 870-micron dust continuum data. Many LABOCA show evidence substructure higher-resolution SABOCA image. In particular, we report on discovery multiple very...
We attempt to characterise the chemical properties of a sample massive clumps IRDCs through multi-molecular line observations. also search for possible evolutionary trends among derived parameters. The are studied using MALT90 survey data obtained with Mopra telescope. spectral-line used in concert our previous LABOCA 870-$\mu$m dust emission data. Most detected species (SiO, C$_2$H, HNCO, HCN, HCO$^+$, HNC, HC$_3$N, and N$_2$H$^+$) show spatially extended towards many sources. fractional...
(Abridged) We aim to determine the degrees of CO depletion, deuterium fractionation, and ionisation in a sample seven massive clumps associated with IRDCs. The APEX telescope was used observe C17O(2-1), H13CO+(3-2), DCO+(3-2), N2H+(3-2), N2D+(3-2) transitions towards clumps. molecules do not appear be significantly depleted observed DCO+/HCO+ N2D+/N2H+ column density ratios are about 0.0002-0.014 0.002-0.028, respectively. former ratio is found decrease as function gas kinetic temperature. A...
The aim of this study is to better understand the physical and chemical properties filamentary IRDC G304.74+01.32. In particular, we investigate kinematics dynamical state cloud clumps within it, amount CO depletion. All submillimetre peak positions in identified from our previous LABOCA 870-micron map were observed C17O(2-1) with APEX. Selected also 13CO(2-1), SiO(5-4), CH3OH(5_k-4_k) transitions at ~1 mm wavelength. C17O lines detected towards all target similar radial velocities,...
Radio emission at cm wavelengths from highly star-forming galaxies, such as SMGs, is dominated by synchrotron radiation arising supernova activity. Using deep, high-resolution ($1\sigma=2.3$ $\mu$Jy beam$^{-1}$; $0.75^{"}$) radio-continuum observations taken the VLA-COSMOS 3 GHz Large Project, we studied radio-emitting sizes of a flux-limited sample SMGs in COSMOS field. Of 39 here, was detected towards 18 them ($\sim46\pm11\%$) with S/N ratios range ${\rm S/N=4.2-37.4}$. 2D elliptical...
Aims.We determine the fractional SiO abundance in high-mass star-forming cores, and investigate its dependence on physical conditions, to provide constraints chemistry models of formation gas phase or via grain mantle evaporation. The work addresses also CH3CCH chemistry, as kinetic temperature is determined using this molecule.
We have mapped four selected about 0.5 deg x deg-sized fields containing Spitzer 8-micron dark regions with APEX/LABOCA at 870 micron. Selected positions in the were observed C17O(2-1) to obtain kinematic information. The obtained LABOCA maps are used conjunction IR images. total number of clumps identified this survey is 91, out which 40 (44%) appear 8 and 24 remaining associated mid-IR emission. Many massive enough allow high-mass star formation, some them already show clear signposts...
Context. The observed spatial scale of the radio continuum emission from star-forming galaxies can be used to investigate extent active star formation, constrain importance cosmic-ray transport, and examine effects galaxy interactions.
We characterise the physical nature of a 1.1 mm-selected, flux-limited, and interferometrically followed up sample SMGs in COSMOS. used MAGPHYS code to fit multiwavelength (UV-radio) SEDs 16 target SMGs. also constructed pure radio our using three different bands (325 MHz, 1.4 GHz, 3 GHz). Moreover, since two sample, AzTEC1 AzTEC3, benefit from previous CO line observations, we studied their properties more detail. found that 63% lie above galaxy main-sequence by than factor 3, hence are...
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.
Infrared dark clouds (IRDCs) likely represent very early stages of high-mass star/star cluster formation. In this study, we aim to determine the physical properties and spatial distribution dense clumps in IRDC MSXDC G304.74+01.32 (G304.74), bring these characteristics into relation theories concerning origin IRDCs their fragmentation star-forming cores. G304.74 was mapped 870 $\mu$m dust continuum with LABOCA bolometer on APEX. Archival MSX IRAS infrared data were used study nature...
<i>Context. <i/>Dense molecular cores are studied to gain insight into the processes causing clouds fragment and form stars. In this study, we concentrate on a region that is assumed represent an early stage of clustered star-formation in giant cloud.<i>Aims. <i/>We aim determine properties spatial distribution dense relatively quiescent Ori B9 cloud, estimate their ages dynamical timescales.<i>Methods. <i/>The cloud was mapped 870 <i>μ<i/>m continuum with APEX/LABOCA, selected positions...
We present APEX observations of C17O(2-1), N2H+(3-2), and N2D+(3-2) towards the subfragments inside prestellar core SMM 6 in Orion B9. combined these spectral line data with our previous SABOCA 350-{\mu}m dust continuum map source. The are characterised by subsonic internal non-thermal motions ({\sigma}NT~0.5cs), most them appear to be gravitationally bound. dispersion N2H+ velocity centroids among condensations is very low (0.02 km/s). CO depletion factors we derive, fD=0.8+/-0.4 -...
Infrared dark clouds (IRDCs) are fruitful objects to study the fragmentation of interstellar filaments and initial conditions early stages high-mass (M>8 M⊙) star formation. We used Yebes 40 m Institut de Radioastronomie Millimétrique (IRAM) 30 radio telescopes carry out first single-pointing spectral line observations towards IRDC G1.75-0.08, which is a filamentary Central Molecular Zone (CMZ) cloud. Our aim reach an improved understanding gas kinematics dynamical state cloud its two...
We aim to determine the physical and chemical properties of dense cores in Orion B9. observed NH3(1,1) (2,2), N2H+(3-2) lines towards submm peak positions. These data are used conjunction with our LABOCA 870 micron dust continuum data. The gas kinetic temperature is between ~9.4-13.9 K. non-thermal velocity dispersion subsonic most cores. linewidth protostellar appears increase increasing bolometric luminosity. core masses very likely drawn from same parent distribution as B North. Starless...