Timothy M. Heckman
A5035116183- Galaxies: Formation, Evolution, Phenomena
- Astronomy and Astrophysical Research
- Stellar, planetary, and galactic studies
- Astrophysics and Star Formation Studies
- Astrophysical Phenomena and Observations
- Gamma-ray bursts and supernovae
- Astronomical Observations and Instrumentation
- Astrophysics and Cosmic Phenomena
- Radio Astronomy Observations and Technology
- Adaptive optics and wavefront sensing
- Spectroscopy and Laser Applications
- Photocathodes and Microchannel Plates
- Solar and Space Plasma Dynamics
- Scientific Research and Discoveries
- Atmospheric Ozone and Climate
- History and Developments in Astronomy
- Calibration and Measurement Techniques
- Particle Accelerators and Free-Electron Lasers
- CCD and CMOS Imaging Sensors
- Atomic and Molecular Physics
- Remote Sensing in Agriculture
- Cosmology and Gravitation Theories
- Impact of Light on Environment and Health
- Geophysics and Gravity Measurements
- Pulsars and Gravitational Waves Research
Johns Hopkins University
2015-2024
Bloomberg (United States)
2015-2024
Arizona State University
2024
Stockholm University
2022
Kavli Institute for the Physics and Mathematics of the Universe
2018
University of Cambridge
2015
UK Astronomy Technology Centre
2014
Royal Observatory
2014
University of Baltimore
2001-2008
National Oceanic and Atmospheric Administration
2007
The Sloan Digital Sky Survey (SDSS) will provide the data to support detailed investigations of distribution luminous and nonluminous matter in universe: a photometrically astrometrically calibrated digital imaging survey π sr above about Galactic latitude 30° five broad optical bands depth g' ∼ 23 mag, spectroscopic approximately 106 brightest galaxies 105 quasars found photometric object catalog produced by survey. This paper summarizes observational parameters products SDSS serves as an...
This paper describes the Seventh Data Release of Sloan Digital Sky Survey (SDSS), marking completion original goals SDSS and end phase known as SDSS-II. It includes 11,663 deg2 imaging data, with most ∼2000 increment over previous data release lying in regions low Galactic latitude. The catalog contains five-band photometry for 357 million distinct objects. survey also repeat on a 120° long, 25 wide stripe along celestial equator Southern Cap, some covered by many 90 individual runs. We...
We examine the properties of host galaxies 22,623 narrow-line AGN with 0.02
We utilize Sloan Digital Sky Survey imaging and spectroscopy of ~53,000 star-forming galaxies at z ~ 0.1 to study the relation between stellar mass gas-phase metallicity. derive oxygen abundances masses using new techniques that make use latest evolutionary synthesis photoionization models. find a tight (±0.1 dex) correlation metallicity spanning over 3 orders magnitude in factor 10 The is relatively steep from 108.5 1010.5 M☉ h, good accord with known trends luminosity metallicity, but...
Abstract We present a comprehensive study of the physical properties ∼ 105 galaxies with measurable star formation in Sloan Digital Sky Survey (SDSS). By comparing information extracted from emission lines continuum properties, we build up picture nature star-forming at z < 0.2. develop method for aperture correction using resolved imaging and show that our takes out essentially all bias rate (SFR) estimates, allowing an accurate estimate total SFRs galaxies. determine SFR density to...
Starburst99 is a comprehensive set of model predictions for spectrophotometric and related properties galaxies with active star formation. The models are an improved extended version the data previously published by Leitherer & Heckman. We have upgraded our code implementing latest stellar evolution Geneva group atmosphere grid compiled Lejeune et al. Several which were not included in previous publication shown here first time. presented homogeneous way five metallicities between Z = 0.040...
The Sloan Digital Sky Survey (SDSS) is an imaging and spectroscopic survey that will eventually cover approximately one-quarter of the celestial sphere collect spectra ≈106 galaxies, 100,000 quasars, 30,000 stars, serendipity targets. In 2001 June, SDSS released to general astronomical community its early data release, roughly 462 deg2 including almost 14 million detected objects 54,008 follow-up spectra. were collected in drift-scan mode five bandpasses (u, g, r, i, z); our 95% completeness...
We give an overview of the Galaxy Evolution Explorer (GALEX), a NASA Mission launched on April 28, 2003. GALEX is performing first space UV sky-survey, including imaging and grism surveys in two bands (1350-1750 Angstroms 1750-2750 Angstroms). The include all-sky survey (m[AB] ~ 20.5), medium 1000 square degrees 23), deep 100 25), nearby galaxy survey. Spectroscopic (R=100-200) are underway with various depths sky coverage. Many targets overlap existing or planned surveys. will use measured...
We develop a new method to constrain the star formation histories, dust attenuation and stellar masses of galaxies. It is based on two absorption-line indices, 4000-Å break strength Balmer index HδA. Together, these indices allow us mean ages galaxies fractional mass formed in bursts over past few Gyr. A comparison with broad-band photometry then yields estimates mass. generate large library Monte Carlo realizations different including starbursts varying range metallicities. use this median...
We present an analysis of the host properties 85224 emission-line galaxies from Sloan Digital Sky Survey. show that Seyferts and LINERs form clearly separated branches on standard optical diagnostic diagrams. derive a new empirical classification scheme which cleanly separates star-forming galaxies, composite AGN-HII we study galaxy these different classes objects. are older, more massive, less dusty concentrated, have higher velocity dispersions lower [OIII] luminosities than Seyfert...
We have created a variety of composite quasar spectra using homogeneous data set over 2200 from the Sloan Digital Sky Survey (SDSS). The sample spans redshift range 0.044 ≤ z 4.789 and an absolute r' magnitude -18.0 to -26.5. input cover observed wavelength 3800–9200 Å at resolution 1800. median covers rest-wavelength 800 8555 reaches peak signal-to-noise ratio 300 per 1 element in rest frame. identified 80 emission-line features spectrum. Emission-line shifts relative nominal laboratory...
We study the relations between stellar mass, star formation history, size and internal structure for a complete sample of 122 808 galaxies drawn from Sloan Digital Sky Survey. show that low-redshift divide into two distinct families at mass 3 × 1010 M⊙. Lower-mass have young populations, low surface densities concentrations typical discs. Their histories are more strongly correlated with density than mass. A significant fraction lowest-mass in our experienced recent starbursts. At given...
This paper describes the Sixth Data Release of Sloan Digital Sky Survey. With this data release, imaging northern Galactic cap is now complete. The survey contains images and parameters roughly 287 million objects over 9583 deg2, including scans a large range latitudes longitudes. also includes 1.27 spectra stars, galaxies, quasars, blank sky (for subtraction) selected 7425 deg2. release much more stellar spectroscopy than was available in previous releases detailed estimates temperatures,...
We measure star formation rates (SFRs) of ≈50,000 optically selected galaxies in the local universe (z ≈ 0.1)—from gas-rich dwarfs to massive ellipticals. obtain dust-corrected SFRs by fitting GALEX (ultraviolet) and SDSS photometry a library dust-attenuated population synthesis models. For star-forming galaxies, our UV-based compare remarkably well with those from SDSS-measured emission lines (Hα). Deviations perfect agreement are shown be due differences dust attenuation estimates. In...
Pan-STARRS1 has carried out a set of distinct synoptic imaging sky surveys including the $3π$ Steradian Survey and Medium Deep in 5 bands ($grizy_{P1}$). The mean 5$σ$ point source limiting sensitivities stacked 3$π$ $grizy_{P1}$ are (23.3, 23.2, 23.1, 22.3, 21.4) respectively. upper bound on systematic uncertainty photometric calibration across is 7-12 millimag depending bandpass. astrometric using Gaia frame comes from comparison results with Gaia: standard deviation median residuals ($...
We refine a technique to measure the absorption-corrected ultraviolet (UV) luminosity of starburst galaxies using rest-frame UV quantities alone and apply it Lyman-limit U dropouts at z ≈ 3 found in Hubble Deep Field (HDF). The method is based on an observed correlation between ratio far-infrared (FIR) fluxes with spectral slope β (a color). A simple fit this relation allows flux absorbed by dust reprocessed FIR be calculated, hence dust-free determined. International Ultraviolet Explorer...
The Sloan Digital Sky Survey (SDSS) has validated and made publicly available its Second Data Release. This data release consists of 3324 deg2 five-band (ugriz) imaging with photometry for over 88 million unique objects, 367,360 spectra galaxies, quasars, stars, calibrating blank sky patches selected 2627 this area, tables measured parameters from these data. reach a depth r ≈ 22.2 (95% completeness limit point sources) are photometrically astrometrically calibrated to 2% rms 100 mas per...
view Abstract Citations (1223) References (138) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS On the Nature and Implications of Starburst-driven Galactic Superwinds Heckman, Timothy M. ; Armus, Lee Miley, George K. We present optical spectroscopic data on ionized nebulae associated with 14 galaxies that are strong far-infrared emitters ("far-IR galaxies," or "FIRGs"). This sample includes three nearest FIRGs (M82, NGC 253, 4945), most famous examples very...
We present the design and performance of multi-object fiber spectrographs for Sloan Digital Sky Survey (SDSS) their upgrade Baryon Oscillation Spectroscopic (BOSS). Originally commissioned in Fall 1999 on 2.5-m aperture Telescope at Apache Point Observatory, produced more than 1.5 million spectra SDSS SDSS-II surveys, enabling a wide variety Galactic extra-galactic science including first observation baryon acoustic oscillations 2005. The were upgraded 2009 are currently use BOSS, flagship...
We describe the calibration status and data products pertaining to GR2 GR3 releases of Galaxy Evolution Explorer (GALEX). These have identical pipeline calibrations that are significantly improved over GR1 release. GALEX continues survey sky in far-ultraviolet (FUV, ~154 nm) near-ultraviolet (NUV, ~232 bands, providing simultaneous imaging with a pair photon-counting, microchannel plate, delay line readout detectors. 1.25° field view detectors well suited ultraviolet observations because...
We use a complete sample of galaxies drawn from the Sloan Digital Sky Survey to study how structure, star formation and nuclear activity depend on local density stellar mass. Local is estimated by counting above fixed absolute magnitude limit within cylinders 2 Mpc in projected radius ±500 km s−1 depth. The mass distribution shifts almost factor two towards higher masses between low- high-density regions. At both strongly density, while structural parameters such as size concentration are...
The Sloan Digital Sky Survey has validated and made publicly available its First Data Release. This consists of 2099 square degrees five-band (u, g, r, i, z) imaging data, 186,240 spectra galaxies, quasars, stars calibrating blank sky patches selected over 1360 this area, tables measured parameters from these data. data go to a depth r ~ 22.6 are photometrically astrometrically calibrated 2% rms 100 milli-arcsec per coordinate, respectively. cover the range 3800--9200 A, with resolution...