A5001119687- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Galaxies: Formation, Evolution, Phenomena
- Astrophysics and Star Formation Studies
- Astronomical Observations and Instrumentation
- Gamma-ray bursts and supernovae
- Adaptive optics and wavefront sensing
- Lung Cancer Diagnosis and Treatment
- Astro and Planetary Science
- Medical Imaging and Pathology Studies
- Calibration and Measurement Techniques
- Spectroscopy and Laser Applications
- Astrophysical Phenomena and Observations
- Estrogen and related hormone effects
- Radiomics and Machine Learning in Medical Imaging
- Astrophysics and Cosmic Phenomena
- CCD and CMOS Imaging Sensors
- HER2/EGFR in Cancer Research
- Atomic and Subatomic Physics Research
- Impact of Light on Environment and Health
- Lung Cancer Treatments and Mutations
- History and Developments in Astronomy
- Tracheal and airway disorders
- Medical Imaging Techniques and Applications
- Salivary Gland Tumors Diagnosis and Treatment
Radboud University Nijmegen
2015-2024
Lockheed Martin (United States)
2014
Université Paris Cité
2014
Délégation Paris 7
2014
Centre National de la Recherche Scientifique
2014
Galaxies, Etoiles, Physique et Instrumentation
2014
Utrecht University
2006-2012
Aarhus University
2011
Astronomical Institute of the Slovak Academy of Sciences
2007-2010
Larsen & Toubro (India)
2010
The Interface Region Imaging Spectrograph (IRIS) small explorer spacecraft provides simultaneous spectra and images of the photosphere, chromosphere, transition region, corona with 0.33-0.4 arcsec spatial resolution, 2 s temporal resolution 1 km/s velocity over a field-of-view up to 175 x arcsec. IRIS was launched into Sun-synchronous orbit on 27 June 2013 using Pegasus-XL rocket consists 19-cm UV telescope that feeds slit-based dual-bandpass imaging spectrograph. obtains in passbands from...
Fast and accurate staging is essential for choosing treatment non–small-cell lung cancer (NSCLC). The purpose of this randomized study was to evaluate the clinical effect combined positron-emission tomography computed (PET–CT) on preoperative NSCLC.
The Panchromatic Hubble Andromeda Treasury is an ongoing Space Telescope Multi-Cycle program to image ∼1/3 of M31's star-forming disk in six filters, spanning from the ultraviolet (UV) near-infrared (NIR). We use Wide Field Camera 3 (WFC3) and Advanced for Surveys (ACS) resolve galaxy into millions individual stars with projected radii 0 20 kpc. full survey will cover a contiguous 0.5 deg2area 828 orbits. Imaging being obtained F275W F336W filters on WFC3/UVIS camera, F475W F814W ACS/WFC,...
The Euclid ERO showcase Euclid's capabilities in advance of its main mission by targeting 17 astronomical objects, including galaxy clusters, nearby galaxies, globular and star-forming regions. A total 24 hours observing time was allocated the early months operation, scientific community engaged through an public data release. We describe development pipeline to create visually compelling images while simultaneously meeting demands within launch leveraging a pragmatic data-driven strategy....
It would be desirable to develop minimally invasive methods of tissue diagnosis from lymph nodes as well solid lesions in the mediastinum. The aim present study was test combined method transesophageal endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) and endobronchial transbronchial needle (EBUS-TBNA) evaluation mediastinal lesions.EUS-FNA EBUS-TBNA were compared 33 patients, for staging lung cancer patients with an established non-small-cell (n = 20) or a suspicious lesion...
We present a study of globular clusters (GCs) in 17 relatively nearby early-type galaxies, based on deep F555W and F814W images from the Wide Field Planetary Camera 2, board Hubble Space Telescope. A detailed analysis color distributions, cluster sizes, luminosity functions is performed compared with GCs Milky Way. In nearly all cases, KMM test returns high confidence level for hypothesis that sum two Gaussians provides better fit to observed distribution than single Gaussian, although...
A detailed description is given of the data analysis leading to discovery young massive star clusters (YMCs) in a sample 21 nearby galaxies. new useful tool, ishape, for derivation intrinsic shape parameters compact objects presented, and some test results are shown. Completeness tests cluster samples discussed, ishape used estimate sizes. Half-light radii 0 - 20 pc derived 2 most cluster-rich galaxies, NGC 1313 5236, which within range spanned by globular Milky Way YMCs LMC starburst...
Star clusters in six nearby spiral galaxies are examined using archive images from the Wide Field Planetary Camera 2 (WFPC2) on board Hubble Space Telescope (HST). The have previously been studied ground and some of them known to possess rich populations "young massive clusters." Comparison with HST indicates a success rate ∼75% for ground-based cluster detections, typical contaminants being blends or loose groupings several stars crowded regions. luminosity functions (LFs) candidates...
<i>Aims. <i/> The initial cluster mass function (ICMF) in spiral discs is constrained and compared with data for old globular clusters young starbursts. <i>Methods. For a given absolute magnitude, the age distribution depends on ICMF. Here, behaviour of median age-magnitude relation analysed detail Schechter ICMFs various cut-off masses, <i>M<i/><sub>c<sub/>. calculated relations are observations brightest galaxies. functions also fitted directly to observed (MFs).<i>Results. <i/>A single...
A study was undertaken to evaluate the clinical impact of endoscopic ultrasound guided fine needle aspiration biopsy (EUS-FNA) in patients with mediastinal masses suspected malignancy.From April 1993 December 1999, 84 were referred for EUS-FNA. In all CT scanning had shown a lesion mediastinum malignancy located adjacent oesophagus. order EUS-FNA, history each patient up referral EUS-FNA reviewed. board thoracic specialists asked decide further course if not been available, and this...
Observations indicate that young massive star clusters in spiral and dwarf galaxies follow a relation between luminosity of the brightest cluster star-formation rate (SFR) host galaxy, sense higher SFRs lead to formation brighter clusters. Assuming empirical maximum SFR reflects an underlying similar mass (M_ecl,max) SFR, we compare resulting SFR(M_ecl,max) with different theoretical models. The correlation is found suggest individual form on free-fall time-scale their pre-cluster...
A search for stellar clusters has been carried out in 18 nearby spiral galaxies, using archive images from the Wide Field Planetary Camera 2 on board Hubble Space Telescope. All of galaxies have previously imaged ground UBVI. catalogue structural parameters, photometry and comments based visual inspection is compiled used to investigate correlations between cluster structure, environment, age mass. Least-squares fits data suggest both full-width at half-maximum (FWHM) half-light radius ()...
We study the stellar cluster population in two adjacent fields nearby, face-on spiral galaxy, M83, using WFC3/HST imaging. The clusters are selected through visual inspection to be centrally concentrated, symmetric, and resolved on images, which allows us differentiate between likely unbound associations. compare our sample with previous studies show that differences catalogues largely due inclusion of large numbers diffuse associations within catalogues. luminosity function is well...
It is now well established that globular clusters (GCs) exhibit star-to-star light-element abundance variations (known as multiple stellar populations, MPs). Such chemical anomalies have been found in (nearly) all the ancient GCs (more than 10 Gyr old) of our Galaxy and its close companions, but so far no model for origin MPs able to reproduce relevant observations. To gain new insights into this phenomenon, we undertaken a photometric Hubble Space Telescope survey study with masses...
We use the Panchromatic Hubble Andromeda Treasury (PHAT) survey dataset to perform spatially resolved measurements of star cluster formation efficiency ($\Gamma$), fraction stellar mass formed in long-lived clusters. robust history and parameter constraints, obtained through color-magnitude diagram analysis populations, study Andromeda's field populations over last $\sim$300 Myr. measure $\Gamma$ 4-8% for young, 10-100 Myr old M31. find that varies systematically across M31 disk, consistent...
We present and describe the astro-photometric catalog of more than 800,000 sources found in Hubble Tarantula Treasury Project (HTTP). HTTP is a Space Telescope (HST) program designed to image entire 30 Doradus region down sub-solar (~0.5 solar masses) mass regime using Wide Field Camera 3 (WFC3) Advanced for Surveys (ACS). observed near ultraviolet (F275W, F336W), optical (F555W, F658N, F775W), infrared (F110W, F160W) wavelengths. The stellar photometry was measured point-spread function...
We introduce a method to relate possible truncation of the star cluster mass function at high end shape luminosity (LF). compare observed LFs five galaxies containing young clusters with synthetic population models varying initial conditions. The LF SMC, LMC and NGC 5236 are characterized by power-law behavior , mean exponent . This can be explained formed constant formation rate, in which maximum per logarithmic age bin is determined size-of-sample effect therefore increases log (age/yr)....
A detailed imaging analysis of the globular cluster (GC) system Sombrero galaxy (NGC 4594) has been accomplished using a six-image mosaic from Hubble Space Telescope Advanced Camera for Surveys. The quality data is such that contamination by foreground stars and background galaxies negligible all but faintest 5% GC luminosity function. This enables study an effectively pure sample 659 GCs until ∼2 mag fainter than turnover magnitude, which occurs at M = -7.60 ± 0.06 assumed m - 29.77. Two...
We present a survey of 130 Galactic and extragalactic young massive clusters (YMCs, $10^4 < M/\msun 10^8$, $10 t/{\rm Myr} 1000$) with integrated spectroscopy or resolved stellar photometry (40 presented here 90 from the literature) use sample to search for evidence ongoing star-formation within clusters. Such episodes secondary (or continuous) are predicted by models that attempt explain observed chemical photometric anomalies in globular as being due formation second population an existing...
We determine the metallicities for globular clusters (GCs) in WLM and IKN dwarf galaxies, using VLT/UVES Keck/ESI spectroscopy. For GC we also measure detailed abundance ratios a number of light, alpha, Fe-peak n-capture elements. find low [Fe/H]=-2.0 -2.1 IKN-5, respectively. estimate that 17%-31% metal-poor stars belong to GC, IKN-5 may even contain similar as whole itself. These high GCs field are tension with formation scenarios require have lost very large fraction their initial mass....
Recently, high-dispersion spectroscopy has demonstrated conclusively that four of the five globular clusters (GCs) in Fornax dwarf spheroidal galaxy are very metal-poor with [Fe/H]<-2. The remaining cluster, 4, [Fe/H]=-1.4. This is stark contrast to field star metallicity distribution which shows a broad peak around [Fe/H]=-1 only few percent stars having If we consider and [Fe/H]<-2 thus find an extremely high GC specific frequency, SN=400, implying by far highest ratio GCs known anywhere....
We use measurements of nitrogen abundances in red giants to search for multiple stellar populations the four most metal-poor globular clusters (GCs) Fornax dwarf spheroidal galaxy (Fornax 1, 2, 3, and 5). New imaging F343N filter, obtained with Wide Field Camera 3 on Hubble Space Telescope, is combined archival F555W F814W observations determine strength NH band near 3370 Å. After accounting observational errors, spread F343N–F555W colors GCs similar that M15 corresponds an abundance range...
Recent studies have started to cast doubt on the assumption that most stars are formed in clusters. Observational of field and star cluster systems nearby galaxies can lead better constraints fraction forming We aim constrain amount formation happening long-lived clusters for four through homogeneous study Using HST/ACS-WFPC2 images NGC45, NGC1313, NGC5236 NGC7793, we estimate histories by means synthetic CMD method. Masses ages estimated using simple stellar population model fitting....
This is the second paper in our series about search for multiple populations Magellanic Cloud star clusters using Hubble Space Telescope. Here we report detection of stellar colour-magnitude diagrams intermediate-age Lindsay 1, NGC 416 and 339. With ages between 6.0 7.5 Gyr, these are youngest ones which chemical abundance spreads have been detected so far. confirms that appearance not restricted to only ancient globular clusters, but may also be a common feature as young 6 Gyr. Our results...