A5058506899- Astrophysics and Star Formation Studies
- Stellar, planetary, and galactic studies
- Galaxies: Formation, Evolution, Phenomena
- Astronomy and Astrophysical Research
- Astro and Planetary Science
- Atmospheric Ozone and Climate
- Spectroscopy and Laser Applications
- Astrophysical Phenomena and Observations
- Atomic and Molecular Physics
- Phase Equilibria and Thermodynamics
- Molecular Spectroscopy and Structure
- Astronomical Observations and Instrumentation
- Ionosphere and magnetosphere dynamics
- Superconducting and THz Device Technology
- Atomic and Subatomic Physics Research
- Inorganic Fluorides and Related Compounds
- Gamma-ray bursts and supernovae
- Climate variability and models
- Laser Applications in Dentistry and Medicine
- Boron and Carbon Nanomaterials Research
- Medical Imaging Techniques and Applications
- Laser-induced spectroscopy and plasma
- Chromatography in Natural Products
- Radiation Detection and Scintillator Technologies
- Advanced Chemical Physics Studies
University of Cologne
2015-2024
Instituto de Radioastronomía Milimétrica
2009-2021
We are conducting COLD GASS, a legacy survey for molecular gas in nearby galaxies. Using the IRAM 30m telescope, we measure CO(1-0) line sample of ~350 (D=100-200 Mpc), massive galaxies (log(M*/Msun)>10.0). The is selected purely according to stellar mass, and therefore provides an unbiased view these systems. By combining data with SDSS photometry spectroscopy, GALEX imaging high-quality Arecibo HI data, investigate partition condensed baryons between stars, atomic 0.1-10L* In this paper,...
We study the relation between molecular gas and star formation in a volume-limited sample of 222 galaxies from COLD GASS survey, with measurements CO(1–0) line IRAM 30-m telescope. The are at redshifts 0.025 < z 0.05 have stellar masses range 10.0 log M★/M⊙ 11.5. complemented by deep Arecibo H i observations homogeneous Sloan Digital Sky Survey GALEX photometry. A reference that includes both ultraviolet (UV) far-infrared data is used to calibrate our estimates rates seven optical/UV bands....
We present a new multi-pixel high resolution (R ≳ 107) spectrometer for the Stratospheric Observatory Far-Infrared Astronomy (SOFIA). The receiver uses 2 × 7-pixel subarrays in orthogonal polarization, each an hexagonal array around central pixel. first results this instrument after commissioning campaigns May and December 2015 science observations performed 2016. is designed to ultimately cover full 1.8−2.5 THz frequency range but its implementation, observing was limited of [CII] line at...
We present the performance of upGREAT heterodyne array receivers on SOFIA telescope after several years operations. This instrument is a multi-pixel high resolution (R > 10^7) spectrometer for Stratospheric Observatory Far-Infrared Astronomy (SOFIA). The use 7-pixel subarrays configured in hexagonal layout around central pixel. low frequency receiver (LFA) has 2x7 pixels (dual polarization), and presently covers 1.83-2.06 THz range, which allows to observe [CII] [OI] lines at 158 um 145...
Abstract Atomic oxygen is a main component of the mesosphere and lower thermosphere Earth, where it governs photochemistry energy balance tracer for dynamical motions. However, its concentration extremely difficult to measure with remote sensing techniques since atomic has few optically active transitions. Current indirect methods involve photochemical models results are not always in agreement, particularly when obtained different instruments. Here we present direct measurements—independent...
Within the framework of HERM33ES key project, we are studying star forming interstellar medium in nearby, metal-poor spiral galaxy M33, exploiting high resolution and sensitivity Herschel. We use PACS SPIRE maps at 100, 160, 250, 350, 500 micron wavelength, to study variation spectral energy distributions (SEDs) with galacto-centric distance. Detailed SED modeling is performed using azimuthally averaged fluxes elliptical rings 2 kpc width, out 8 Simple isothermal two-component grey body...
Power spectra of deprojected images late-type galaxies in gas or dust emission are very useful diagnostics the dynamics and stability their interstellar medium. Previous studies have shown that power can be approximated as two laws, a shallow one on large scales (larger than 500 pc) steeper small scales, with break between corresponding to line-of-sight thickness galaxy disk. The separates 3D behavior medium controlled by star formation feedback, from 2D driven density waves these regimes...
FEEDBACK is a SOFIA legacy program dedicated to study the interaction of massive stars with their environment. It performs survey 11 galactic high mass star forming regions in 158 $μ$m (1.9 THz) line CII and 63 (4.7 OI. We employ 14 pixel LFA 7 HFA upGREAT instrument spectrally resolve (0.24 MHz) these FIR structure lines. With an observing time 96h, we will cover $\sim$6700 arcmin$^2$ at 14.1$''$ angular resolution for 6.3$''$ OI line. The observations started spring 2019 (Cycle 7). Our aim...
Radiative and mechanical feedback of massive stars regulates star formation galaxy evolution. Positive triggers the creation new by collecting dense shells gas, while negative disrupts shredding molecular clouds. Although key to understanding formation, their relative importance is unknown. Here, we report velocity-resolved observations from SOFIA (Stratospheric Observatory for Infrared Astronomy) legacy program FEEDBACK star-forming region RCW 120 in [CII] 1.9-THz fine-structure line,...
Abstract Molecular hydrogen clouds are a key component of the interstellar medium because they birthplaces for stars. They embedded in atomic gas that pervades space. However, details how molecular assemble from and interact with still largely unknown. As result new observations 158 μm line ionized carbon [CII] Cygnus region within FEEDBACK program on SOFIA (Stratospheric Observatory Infrared Astronomy), we present compelling evidence unveils dynamic interactions between cloud ensembles....
We study the far-infrared emission from nearby spiral galaxy M33 in order to investigate dust physical properties such as temperature and luminosity density across galaxy. Taking advantage of unique wavelength coverage (100, 160, 250, 350 500 micron) Herschel Space Observatory complementing our dataset with Spitzer-IRAC 5.8 8 micron Spitzer-MIPS 24 70 data, we construct maps by fitting two modified blackbodies a fixed emissivity index 1.5. find that 'cool' grains are heated at temperatures...
Context: The emission line of [CII] at 158 micron is one the strongest cooling lines interstellar medium (ISM) in galaxies. Aims: Disentangling relative contributions different ISM phases to emission, a major topic HerM33es program, Herschel key project study nearby spiral galaxy M33. Methods: Using PACS, we have mapped micron, [OI] 63 and other FIR 2'x2' region northern arm M33, centered on HII BCLMP302. At peak H-alpha observed addition velocity resolved spectrum using HIFI. We use...
Revealing the 3D dynamics of HII regions and their associated molecular clouds is important for understanding longstanding problem as to how stellar feedback affects density structure kinematics interstellar medium. We employed observations region RCW 120 in [CII], observed within SOFIA legacy program FEEDBACK, $^{12}$CO $^{13}$CO (3$\to$2) lines, obtained with APEX. In addition we used HI data from Southern Galactic Plane Survey. Two radiative transfer models were fit data. A line profile...
Context. The interaction of expanding H II regions with their environmental clouds is one the central questions driving Stratospheric Observatory for Infrared Astronomy (SOFIA) legacy program FEEDBACK. Aims. We want to understand prototypical NGC 7538 region neighboring molecular cloud hosting several active star-forming regions. Methods. Using SOFIA, we mapped an area ~210′ 2 (~125 pc ) around in velocity-resolved ionized carbon fine-structure line [CII] at 1.9 THz (158 μm). Complementary...
Observations with the Herschel Space Telescope have established that most of star forming gas is organised in interstellar filaments, a finding supported by numerical simulations supersonic medium (ISM) where dense filamentary structures are ubiquitous. We aim to understand formation these performing observations covering $^{12}$CO(4-3), $^{12}$CO(3-2), and various CO(2-1) isotopologue lines Musca filament, using APEX telescope. The observed CO intensities line ratios cannot be explained PDR...
We present an analysis of the first space-based far-IR-submm observations M 33, which measure emission from cool dust and resolve giant molecular cloud complexes. With roughly half-solar abundances, M33 is a step towards young low-metallicity galaxies where submm may be able to provide alternative CO mapping their H$_2$ content. In this Letter, we cross-section $\sigma$ using SPIRE recent \HI\ observations; variation in near-solar neighborhood about with maximum being south nucleus....
Aims. We aim to better understand the heating of gas by observing prominent cooling line [C ii] at 158 μm in low-metallicity environment Local Group spiral galaxy M 33 on scales 280 pc. In particular, we describe variation photoelectric efficiency with galactic environment.
Strong winds and ultraviolet (UV) radiation from O-type stars disrupt ionize their molecular core birthplaces, sweeping up material into parsec-size shells. Owing to dissociation by starlight, the thinnest shells are expected host low abundances therefore little star formation. Here, we expand previous maps made with observations using IRAM 30 m telescope (at 11″ ≃ 4500 AU resolution) present square-degree 12 CO 13 ( J = 2–1) of wind-driven “Veil bubble” that surrounds Trapezium cluster its...
The [CII] fine-structure transition at 158 micron is frequently the brightest far-infrared line in galaxies. Due to its low ionization potential, C+ can trace ionized, atomic, and molecular phases of ISM. We present velocity resolved [NII] pointed observations from SOFIA/GREAT on ~500 pc scales nearby galaxies M101 NGC 6946 investigate multi-phase origin emission over a range environments. show that ionized gas makes negligible contribution these positions using observations. spectrally...
Over the past few years several studies have provided estimates of SFR (star-formation rate) or total infrared luminosity from just one band. However these relations are generally derived for entire galaxies, which known to contain a large scale diffuse emission that is not necessarily related latest star-formation episode. We provide new estimate resolved star-forming regions at 100 mum and 160 mum. select individual in nearby (840 kpc) galaxy M33. combining Halpha 24 calibrate as...
<i>Aims. <i/>Within the framework of HERM33ES key program, using high resolution and sensitivity <i>Herschel<i/> photometric data, we study compact emission in Local Group spiral galaxy M 33 to investigate nature SPIRE sources. We extracted a catalogue sources at 250 <i>μ<i/>m order this emission. Taking advantage unprecedented these wavelengths, also focus on more precise some striking H<i>α<i/> shells northern part galaxy.<i>Methods. <i/>We present 159 identified by SExtractor band that is...
We aim to better understand the emission of molecular tracers diffuse and dense gas in giant clouds influence that metallicity, optical extinction, density, far-UV field, star formation rate have on these tracers. Using IRAM 30m telescope, we detected HCN, HCO+, 12CO, 13CO six GMCs along major axis M33 at a resolution ~ 114pc out radial distance 3.4kpc. Optical, far-infrared, submillimeter data from Herschel other observatories complement observations. To interpret observed line emission,...
We present [CII] 158 $\mu$m and [OI] 63 observations of the bipolar HII region RCW 36 in Vela C molecular cloud, obtained within SOFIA legacy project FEEDBACK, which is complemented with APEX $^{12/13}$CO(3-2) Chandra X-ray (0.5-7 keV) data. This shows that ring, forming waist nebula, expands a velocity 1 - 1.9 km s$^{-1}$. also observe an increased linewidth ring indicating turbulence driven by energy injection from stellar feedback. The cavity hosts blue-shifted expanding shells at...
The aim of the present work is to study structure and gas kinematics in photodissociation regions (PDRs) around compact HII S235A S235C. We observe [CII], [13CII] [OI] line emission, using SOFIA/upGREAT complement them by data HCO+ CO. use measure optical depth [CII] find that profiles are influenced self-absorption, while remains unaffected these effects. Hence, for dense PDRs, emission a better tracer kinematics. up 10 S235A. an expanding motion [CII]-emitting layer PDRs into front...