Jakob S. den Brok
A5037402936- Galaxies: Formation, Evolution, Phenomena
- Astrophysics and Star Formation Studies
- Spectroscopy and Laser Applications
- Gamma-ray bursts and supernovae
- Astrophysical Phenomena and Observations
- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Astrophysics and Cosmic Phenomena
- Astronomical Observations and Instrumentation
- Atmospheric Ozone and Climate
- Phase Equilibria and Thermodynamics
- Radio Astronomy Observations and Technology
- Advanced Fiber Laser Technologies
- CCD and CMOS Imaging Sensors
- Pharmacological Effects and Assays
- Scientific Research and Discoveries
- Adaptive optics and wavefront sensing
- Nuclear Physics and Applications
- Atomic and Subatomic Physics Research
- Advanced Measurement and Metrology Techniques
- Veterinary Equine Medical Research
- Black Holes and Theoretical Physics
- Geomagnetism and Paleomagnetism Studies
- Power Systems and Technologies
- Geophysics and Gravity Measurements
University of Bonn
2020-2024
Center for Astrophysics Harvard & Smithsonian
2023-2024
ETH Zurich
2020-2023
Abstract We present PHANGS–ALMA, the first survey to map CO J = 2 → 1 line emission at ∼1″ ∼100 pc spatial resolution from a representative sample of 90 nearby ( d ≲ 20 Mpc) galaxies that lie on or near z 0 “main sequence” star-forming galaxies. traces bulk distribution molecular gas, which is cold, phase interstellar medium. At achieved by each beam reaches size typical individual giant cloud, so these data can be used measure demographics, life cycle, and physical state clouds across...
We measure the low-J CO line ratio R21=CO(2-1)/CO(1-0), R32=CO(3-2)/CO(2-1), and R31 = CO(3-2)/CO(1-0) using whole-disk maps of nearby galaxies. draw CO(2-1) from PHANGS--ALMA, HERACLES, follow-up IRAM surveys; CO(1-0) COMING Nobeyama Atlas Nearby Spiral Galaxies; CO(3-2) JCMT NGLS APEX LASMA mapping. Altogether this yields 76, 47, 29 R21, R32, at 20" \sim 1.3 kpc resolution, covering 43, 34, 20 Disk galaxies with high stellar mass, log10 M_* [Msun]=10.25-11 star formation rate, SFR=1-5...
The PHANGS collaboration has been building a reference dataset for the multi-scale, multi-phase study of star formation and interstellar medium in nearby galaxies. With successful launch commissioning JWST, we can now obtain high-resolution infrared imaging to probe youngest stellar populations dust emission on scales clusters molecular clouds ($\sim$5-50 pc). In Cycle 1, is conducting an 8-band survey from 2-21$\mu$m 19 spiral CO(2-1) mapping, optical integral field spectroscopy, UV-optical...
Both the CO(2-1) and CO(1-0) lines are used to trace mass of molecular gas in galaxies. Translating estimates between studies using different requires a good understanding behaviour CO(2-1)-to-CO(1-0) ratio, $R_{21}$. We compare new, high quality data from IRAM 30-m EMPIRE survey latest available maps HERACLES, PHANGS-ALMA, new M51 Large Program. This allows us measure $R_{21}$ across full star-forming disc nine nearby, massive, spiral galaxies at 27" (${\sim} 1{-}2$ kpc) resolution. find an...
Abstract We present the active galactic nucleus (AGN) catalog and optical spectroscopy for second data release of Swift BAT AGN Spectroscopic Survey (BASS DR2). With this DR2 we provide 1449 spectra, which 1182 are released first time, 858 hard-X-ray-selected AGNs in 70-month sample. The majority spectra (801/1449, 55%) newly obtained from Very Large Telescope (VLT)/X-shooter or Palomar/Doublespec. Many have both higher resolution ( R > 2500, N ∼ 450) and/or very wide wavelength coverage...
Abstract We present measurements of broad emission lines and virial estimates supermassive black hole masses ( M BH ) for a large sample ultrahard X-ray-selected active galactic nuclei (AGNs) as part the second data release BAT AGN Spectroscopic Survey (BASS/DR2). Our catalog includes total 689 AGNs, determined from H α , β Mg ii λ 2798, and/or C iv 1549 lines. The core 512 AGNs drawn 70 month Swift/BAT all-sky catalog. also provide 177 additional that are deeper survey data. study links...
The BAT AGN Spectroscopic Survey (BASS) is designed to provide a highly complete census of the key physical parameters supermassive black holes (SMBHs) that power local active galactic nuclei (AGN) (z<0.3), including their bolometric luminosity, hole mass, accretion rates, and line-of-sight gas obscuration, distinctive properties host galaxies (e.g., star formation masses, fractions). We present an overview BASS data release 2 (DR2), unprecedented spectroscopic survey in spectral range,...
Abstract We determine the low-redshift X-ray luminosity function, active black hole mass function (BHMF), and Eddington ratio distribution (ERDF) for both unobscured (Type 1) obscured 2) galactic nuclei (AGNs), using unprecedented spectroscopic completeness of BAT AGN Spectroscopic Survey (BASS) data release 2. In addition to a straightforward 1/ V max approach, we also compute intrinsic distributions, accounting sample truncation by employing forward-modeling approach recover observed BHMF...
We present a high-resolution view of bubbles within The Phantom Galaxy (NGC 628); nearby (~10Mpc), star-forming (~2Msun/yr), face-on (i~9deg) grand-design spiral galaxy. With new data obtained as part the PHANGS-JWST treasury program, we perform detailed case-study two regions interest, one which contains largest and most prominent bubble in galaxy (The Void; over 1kpc diameter), other being smaller region that may be precursor to such large Precursor Void). When comparing matched resolution...
Abstract Determining how the galactic environment, especially high gas densities and complex dynamics in bar-fed galaxy centers, alters star formation efficiency (SFE) of molecular is critical to understanding evolution. However, these same physical or dynamical effects also alter emissivity properties CO, leading variations CO-to-H 2 conversion factor ( α CO ) that impact assessment column thus SFE. To address such issues, we investigate dependence on local velocity dispersion at 150 pc...
Abstract We present new central stellar velocity dispersions for 484 Sy 1.9 and 2 from the second data release of Swift/BAT AGN Spectroscopic Survey (BASS DR2). This constitutes largest study dispersion measurements in X-ray-selected obscured active galactic nuclei (AGN) with 956 independent Ca ii H K λ 3969, 3934 Mg I 5175 region (3880–5550 Å) calcium triplet (8350–8730 642 spectra mainly VLT/X-Shooter or Palomar/DoubleSpec. Our sample spans 40–360 km s 1 , corresponding to 4–5 orders...
Abstract To understand the origin of nuclear (≲100 pc) millimeter-wave (mm-wave) continuum emission in active galactic nuclei (AGNs), we systematically analyzed subarcsecond resolution Band-6 (211–275 GHz) Atacama Large Millimeter/submillimeter Array data 98 nearby AGNs ( z < 0.05) from 70 month Swift/BAT catalog. The sample, almost unbiased for obscured systems, provides largest number to date with high mm-wave spatial sampling (∼1–200 pc), and spans broad ranges 14–150 keV luminosity {...
Abstract We present the second catalog and data release of optical spectral line measurements active galactic nucleus (AGN) demographics BAT AGN Spectroscopic Survey, which focuses on Swift-BAT hard X-ray detected AGNs. use spectra from dedicated campaigns publicly available archives to investigate properties most AGNs listed in 70 month all-sky catalog; specifically, 743 746 unbeamed unlensed (99.6%). find a good correspondence between emission widths hydrogen column density distributions...
We use new HCN(1-0) data from the ALMOND (ACA Large-sample Mapping Of Nearby galaxies in Dense gas) survey to trace kpc-scale molecular gas density structure and CO(2-1) PHANGS-ALMA bulk across 25 nearby, star-forming galaxies. At 2.1 kpc scale, we measure density-sensitive HCN/CO line ratio SFR/HCN star formation efficiency denser medium. 150 pc structural dynamical properties of via emission, which is linked lower resolution using an intensity-weighted averaging method. find positive...
Abstract We explore the relationship between mid-infrared (mid-IR) and CO rotational line emission from massive star-forming galaxies, which is one of tightest scalings in local universe. assemble a large set unresolved moderately (∼1 kpc) spatially resolved measurements (1–0) (2–1) intensity, I , mid-IR MIR at 8, 12, 22, 24 μ m. The versus reasonably described by power law with slopes 0.7–1.2 normalization ∼ 1 K km s −1 MJy sr . Both intercepts vary systematically choice band. comparison...
Abstract Virial black hole (BH) mass ( M BH ) determination directly involves knowing the broad-line region (BLR) clouds’ velocity distribution, their distance from central supermassive R BLR ), and virial factor f ). Understanding whether biases arise in estimation with increasing obscuration is possible only by studying a large N > 100) statistical sample of obscuration-unbiased (hard) X-ray-selected active galactic nuclei (AGNs) rest-frame near-infrared (0.8–2.5 μ m) since it...
Context. Stellar feedback is one of the fundamental factors regulating evolution galaxies. However, we still do not have access to strong observational constraints on relative importance different mechanisms (e.g. radiation, ionised gas pressure, stellar winds) in driving H II region and molecular cloud disruption. To quantify compare mechanisms, size an crucial, whereas samples well-resolved regions are scarce. Aims. We constrain various from young massive star populations by resolving...
Abstract We present the BAT AGN Spectroscopic Survey (BASS) Near-infrared Data Release 2 (DR2), a study of 168 nearby ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mover accent="true"> <mml:mrow> <mml:mi>z</mml:mi> </mml:mrow> <mml:mo>¯</mml:mo> </mml:mover> <mml:mo>=</mml:mo> <mml:mn>0.04</mml:mn> </mml:math> , z < 0.6) active galactic nuclei (AGN) from all-sky Swift Burst Array Telescope X-ray survey observed with Very Large (VLT)/X-shooter in...
Abstract We compare embedded young massive star clusters (YMCs) to (sub-)millimeter line observations tracing the excitation and dissociation of molecular gas in starburst ring NGC 1365. This galaxy hosts one strongest nuclear starbursts richest populations YMCs within 20 Mpc. Here we combine near-/mid-IR PHANGS–JWST imaging with new Atacama Large Millimeter/submillimeter Array multi- J CO (1–0, 2–1 4–3) [ C i ] (1–0) mapping, which use trace via R 42 = I CO(4−3) / CO(2−1) 21 CO(1−0) CICO...
The molecular-to-atomic gas ratio is crucial to our understanding of the evolution interstellar medium (ISM) in galaxies. We investigated balance between atomic (Σ HI ) and molecular H2 surface densities eight nearby star-forming galaxies using new high-quality observations from MeerKAT ALMA (for H I CO, respectively). defined as R mol = Σ /Σ measured how depends on local conditions galaxy disks multiwavelength observations. find that, depending galaxy, detected at > 3 σ out 20 − 120 kpc...
The complex physical, kinematic, and chemical properties of galaxy centres make them interesting environments to examine with molecular line emission. We present new $2-4$" (${\sim}75{-}150$ pc at $7.7$ Mpc) observations 2 3 mm covering the central $50$" (${\sim}1.9$ kpc) nearby double-barred spiral NGC 6946 obtained IRAM Plateau de Bure Interferometer. detect spectral lines from ten molecules: CO, HCN, HCO$^+$, HNC, CS, HC$_3$N, N$_2$H$^+$, C$_2$H, CH$_3$OH, H$_2$CO. complemented these...
Quasar strong gravitational lenses are important tools for putting constraints on the dark matter distribution, energy contribution, and Hubble-Lemaître parameter. We aim to present a new supervised machine learning-based method identify these in large astrometric surveys. The Gaia Focused Product Release (FPR) GravLens catalogue is designed identification of multiply imaged quasars, as it provides astrometry photometry all sources field 4.7 million quasars. Our approach automatically...
Abstract The distribution and physical conditions of molecular gas are closely linked to star formation the subsequent evolution galaxies. Emission from carbon monoxide (CO) its isotopologues traces bulk provides constraints on through their line ratios. However, a comprehensive understanding how particular choice modeling approach impacts derived properties remains incomplete. Here, we study nearby starburst galaxy M82, known for intense emission, using large set available multi-CO...
We present Surveying the Whirlpool at Arcseconds with NOEMA (SWAN), a high-resolution, high-sensitivity survey to map molecular lines in 3mm band M51 (the galaxy). SWAN has obtained largest (∼ 5 7,kpc^2) of emission ∼cloud-scale resolution ($3 125,$pc) an external galaxy date. Here, we describe observations and data reduction ∼214,hours interferometric from Northern Extended Millimetre Array (NOEMA) ∼55,hours tailored new 30m telescope Institut de radioastronomie millimétrique (IRAM), as...
Abstract Combining Atacama Large Millimeter/submillimeter Array CO(2–1) mapping and JWST near- mid-infrared imaging, we characterize the relationship between polycyclic aromatic hydrocarbon (PAH) emission at ≈100 pc resolution in 70 nearby star-forming galaxies. Leveraging a new Cycle 2 Treasury program targeting galaxies, expand sample size by more than an order of magnitude compared to previous CO–PAH comparisons. In regions galaxies where most gas is likely be molecular, find strong...