Danial Langeroodi
A5084553879- Galaxies: Formation, Evolution, Phenomena
- Astronomy and Astrophysical Research
- Gamma-ray bursts and supernovae
- Astrophysics and Star Formation Studies
- Stellar, planetary, and galactic studies
- Astrophysical Phenomena and Observations
- Astrophysics and Cosmic Phenomena
- Adaptive optics and wavefront sensing
- Pulsars and Gravitational Waves Research
- Heat Transfer Mechanisms
- CCD and CMOS Imaging Sensors
- Spectroscopy and Laser Applications
- Superconducting Materials and Applications
- Cosmology and Gravitation Theories
- Advanced Materials Characterization Techniques
- Astronomical Observations and Instrumentation
- Geomagnetism and Paleomagnetism Studies
- X-ray Diffraction in Crystallography
- Real-time simulation and control systems
- Spacecraft and Cryogenic Technologies
- Geophysics and Gravity Measurements
- Advanced optical system design
- Color Science and Applications
- Nuclear Physics and Applications
- Molecular Spectroscopy and Structure
University of Copenhagen
2022-2024
Leiden University
2022
Ultraviolet light from early galaxies is thought to have ionized gas in the intergalactic medium. However, there are few observational constraints on this epoch because of faintness those and redshift their optical into infrared. We report observation, JWST imaging, a distant galaxy that magnified by gravitational lensing. spectroscopy galaxy, at rest-frame wavelengths, detects strong nebular emission lines attributable oxygen hydrogen. The measured z = 9.51 ± 0.01, corresponding 510 million...
Abstract We present the ultraviolet luminosity function and an estimate of cosmic star formation rate density at 8 < z 13 derived from deep NIRCam observations taken in parallel with MIRI Deep Survey Hubble Ultra Field (HUDF), covering field 2. Our (40 hr) reach F277W magnitude 30.8 (5 σ ), more than 2 mag deeper JWST public data sets already analyzed to find high-redshift galaxies. select a sample 44 > galaxy candidates based on their dropout nature F115W and/or F150W filters, high...
Abstract We present ultraviolet/optical/near-infrared observations and modeling of Type II supernovae (SNe II) whose early time ( δ t < 2 days) spectra show transient, narrow emission lines from shock ionization confined r 10 15 cm) circumstellar material (CSM). The observed electron-scattering broadened line profiles (i.e., IIn-like) H i , He i/ii C iv N iii/iv/v the CSM persist on a characteristic timescale IIn ) that marks transition to lower-density emergence Doppler-broadened...
We present the Young Supernova Experiment Data Release 1 (YSE DR1), comprised of processed multi-color Pan-STARRS1 (PS1) griz and Zwicky Transient Facility (ZTF) gr photometry 1975 transients with host-galaxy associations, redshifts, spectroscopic/photometric classifications, additional data products from 2019 November 24 to 2021 December 20. YSE DR1 spans discoveries observations young fast-rising supernovae (SNe) that persist for over a year, redshift distribution reaching z~0.5. relative...
Abstract We make use of JWST medium-band and broadband NIRCam imaging, along with ultradeep MIRI 5.6 μ m in the Hubble eXtreme Deep Field to identify prominent line emitters at z ≃ 7–8. Out a total 58 galaxies 7–8, we find 18 robust candidates (≃31%) for (H β + [O iii ]) emitters, based on their enhanced fluxes F430M F444W filters, EW 0 +[O ≃87–2100 Å. Among these 16 lie coverage area 12 exhibit clear flux excess m, indicating simultaneous presence H α emission ) ≃200–3000 This is first time...
Abstract A tight positive correlation between the stellar mass and gas-phase metallicity of galaxies has been observed at low redshifts. The redshift evolution this can strongly constrain theories galaxy evolution. advent JWST allows probing mass–metallicity relation redshifts far beyond what was previously accessible. Here we report discovery two emission line 8.15 8.16 in NIRCam imaging NIRSpec spectroscopy targets gravitationally lensed by cluster RX J2129.4+0005. We measure their...
We present MIRI/JWST medium-resolution spectroscopy (MRS) and imaging (MIRIM) of the lensed galaxy MACS1149-JD1 at a redshift z = 9.1092 ± 0.0002, when Universe was about 530 Myr old. detect, for first time, spatially resolved H α emission in above nine. The structure emitting gas consists two clumps, S N, carrying 60% 40% total flux, respectively. luminosity implies an instantaneous star-formation rate range 3.2 0.3 5.3 0.4 M ⊙ yr −1 sub-solar solar metallicities. ionizing photon production...
Abstract We present deep James Webb Space Telescope (JWST)/Mid-Infrared Instrument (MIRI) F560W observations of a flux-limited, Atacama Large Millimeter/submillimeter Array (ALMA)-selected sample 28 galaxies at z = 0.5–3.7 in the Hubble Ultra Deep Field (HUDF). The data from MIRI Imaging Survey (MIDIS) reveal stellar structure HUDF rest-frame wavelengths λ > 1 μ m for first time. revise mass estimates using new JWST photometry and find good agreement with pre-JWST analyses; few...
Abstract By using an ultradeep JWST/MIRI image at 5.6 μ m in the Hubble eXtreme Deep Field, we constrain role of strong H α emitters (HAEs) during “cosmic reionization” z ≃ 7–8. Our sample HAEs is comprised young (<35 Myr) galaxies, except for one single galaxy (≈300 Myr), with low stellar masses (≲10 9 M ⊙ ). These show a wide range rest-frame UV continuum slopes ( β ), median value = −2.15 ± 0.21, which broadly correlates mass. We estimate ionizing photon production efficiency ξ ion,0 )...
Abstract Cold, substellar objects such as brown dwarfs have long been recognized contaminants in color-selected samples of active galactic nuclei (AGNs). In particular, their near- to mid-infrared colors (1–5 μ m) can closely resemble the V-shaped ( f λ ) spectra highly reddened accreting supermassive black holes (“little red dots”), especially at 6 < z 7. Recently, a NIRCam-selected sample little dots over 45 arcmin 2 has followed up with deep NIRSpec multiobject prism spectroscopy...
We present optical and near-infrared (NIR) observations of the Type Icn supernova (SN Icn) 2022ann, fifth member its newly identified class SNe. Its early spectra are dominated by narrow carbon oxygen P-Cygni features with absorption velocities 800 km/s; slower than other SNe indicative interaction a dense, H/He-poor circumstellar medium (CSM) that is outflowing typical Wolf-Rayet wind velocity $>$1000 km/s. identify helium in NIR obtained two weeks after maximum at three weeks,...
Abstract We study the stellar population properties of 182 spectroscopically confirmed (MUSE/VLT) Ly α emitters (LAEs) and 450 photometrically selected Lyman-break galaxies (LBGs) at z = 2.8–6.7 in Hubble Extreme Deep Field. Leveraging combined power Space Telescope JWST NIRCam MIRI observations, we analyze their rest-frame UV-through-near-IR spectral energy distributions, with playing a crucial role robustly assessing LAEs’ masses ages. Our LAEs are low-mass objects <mml:math...
Abstract We investigate the properties of strong (H β + [O iii ]) emitters before and after end “Epoch Reionization” from z = 8 to 5.5. make use ultradeep JWST / NIRCam imaging in parallel field (P2) MIRI Deep Imaging Survey (MIDIS) Hubble eXtreme Field (H-XDF), order select prominent (with rest-frame equivalent width (EW 0 ) ≳ 100 Å) at 5.5–7, based on their flux density enhancement F356W band with respect spectral energy distribution continuum. complement our selection other literature...
We present panchromatic observations and modeling of calcium-strong supernovae (SNe) 2021gno in the star-forming host galaxy NGC 4165 (D = 30.5 Mpc) 2021inl outskirts elliptical 4923 80 Mpc), both monitored through Young Supernova Experiment (YSE) transient survey. The multi-color light curves SNe show two peaks, former peak being derived from shock cooling emission (SCE) and/or interaction with circumstellar material (CSM). primary SN is coincident luminous, rapidly decaying X-ray ($L_x 5...
Context. Complex organic species are known to be abundant toward low- and high-mass protostars. No statistical study of these a large sample protostars with the Atacama Large Millimeter/submillimeter Array (ALMA) has been carried out so far. Aims. We aim six N-bearing species: methyl cyanide (CH 3 CN), isocyanic acid (HNCO), formamide (NH 2 CHO), ethyl (C H 5 vinyl CN) methylamine NH ) in line-rich Methods. From ALMA Evolutionary High Mass Protocluster Formation Galaxy survey, 37 most hot...
ABSTRACT We present a new analysis of the rest-frame ultraviolet (UV) and optical spectra sample three z &gt; 8 galaxies discovered behind gravitational lensing cluster RX J2129.4+0009. combine these observations with 7.5 from literature, for which similar measurements are available. As already pointed out in other studies, high [O iii]λ5007/[O ii]λ3727 ratios (O32) steep UV continuum slopes (β) consistent values observed low-redshift Lyman emitters, suggesting that such contribute to...
We combine the deepest X-ray survey from Chandra Deep Field-South (CDF-S) `7-Ms' with mid-infrared (5.6$ \mu m$) image JWST/MIRI Imaging Survey (MIDIS) in Hubble Ultra-Deep Field (HUDF) to study infrared counterparts and point-source emission of 31 sources a median, intrinsic, rest-frame luminosity $\log_{10}(L_{\rm Xc}^{\rm 0.5-7keV})$=42.04$\pm$0.22 erg $\rm s^{-1}$. The sample includes 24 AGN redshift range, as set by detectability, $z \simeq 0.5-3$. Through multi-wavelength morphological...
Abstract We present Young Supernova Experiment grizy photometry of SN 2021hpr, the third Type Ia supernova sibling to explode in Cepheid calibrator galaxy, NGC 3147. Siblings are useful for improving SN-host distance estimates and investigating their contributions toward intrinsic scatter (post-standardization residual estimates). thus develop a principled Bayesian framework analyzing siblings. At its core is cosmology-independent relative parameter, σ Rel : dispersion siblings one another...
Abstract We report the discovery of Cerberus, an extremely red object detected with MIRI Deep Imaging Survey (MIDIS) observations in F1000W filter Hubble Ultra Field. The is at signal-to-noise ratio (S/N) ∼ 6, 27 mag, and undetected NIRCam data gathered by JWST Advanced Extragalactic (JADES), fainter than 30.0–30.5 mag 5 σ detection limits individual bands, as well MIDIS F560W ultradeep (∼29 ). Analyzing spectral energy distribution built low-S/N (<5) measurements optical-to-mid-infrared...
Recent compilations of NIRSpec emission line galaxies have shown a mild redshift evolution the FMR at $z > 4$, indicating that alone is not fully capable capturing mass-metallicity relation: 4$ appear more metal-poor than predictions. There evidence most metal-deficient high-redshift are also compact. In this work, we further investigate anti-correlation by leveraging wealth data gathered through first cycle JWST. We compile sample 427 3$ covered both prism and NIRCam short-wavelength...
We present optical, ultraviolet, and infrared data of the type II supernova (SN II) 2020jfo at 14.5 Mpc. This wealth multiwavelength allows to compare different metrics commonly used estimate progenitor masses SN for same object. Using its early light curve, we infer had a radius $\approx$700 $R_{\odot}$, consistent with red supergiants initial mass $M_{\rm ZAMS}=$11-13 $M_{\odot}$. The decline in late-time curve is best fit by ${}^{56}$Ni 0.018$\pm$0.007 $M_{\odot}$ that ejected from II-P...
We present ultraviolet/optical/near-infrared observations and modeling of Type II supernovae (SNe II) whose early-time ($\delta t < 2$ days) spectra show transient, narrow emission lines from shock ionization confined ($r 10^{15}$ cm) circumstellar material (CSM). The observed electron-scattering broadened line profiles (i.e., IIn-like) HI, He I/II, C III/IV, N III/IV/V the CSM persist on a characteristic timescale ($t_{\rm IIn}$) that marks transition to lower-density emergence...
We present the ultraviolet luminosity function and an estimate of cosmic star formation rate density at $88$ galaxy candidates based on their dropout nature in F115W and/or F150W filters, a high probability for photometric redshifts, estimated with three different codes, being $z>8$, good fits $χ^2$ calculations, predominant solutions compared to $z<8$ alternatives. find mild evolution from $z\sim13$ $z\sim8$, i.e., only small increase average number $\sim$0.2 dex, while faint-end...
The mid-infrared spectra of star-forming galaxies (SFGs) are characterized by characteristic broad PAH emission features at 3-20 $\mu$m. As these redshifted, they predicted to dominate the flux specific wavelengths, leading substantial redshift-dependent color variations in broad-band photometry. advent JWST for first time allows study this effect normal SFGs. Based on spectral energy distribution templates, we here present tracks (4.4, 7.7, 10, 15, and 18 $\mu$m) color-color diagrams...