Milan Bogosavljevic

Milan Bogosavljevic
New York University Abu Dhabi · Physics

PhD
New York University Abu Dhabi

About

46
Publications
2,020
Reads
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2,664
Citations
Additional affiliations
September 2017 - present
New York University Abu Dhabi
Position
  • Lecturer
January 2014 - January 2015
Sultan Qaboos University
Position
  • Visiting Faculty
July 2010 - July 2017
Astronomska opservatorija
Position
  • Professor
Education
September 2001 - January 2010
California Institute of Technology
Field of study
  • Astrophysics

Publications

Publications (46)
Preprint
We present new measurements of the spatial distribution and kinematics of neutral hydrogen in the circumgalactic and intergalactic medium surrounding star-forming galaxies at z ~ 2. Using the spectra of ~ 3000 galaxies with redshifts +/- 0.4 from the Keck Baryonic Structure Survey (KBSS), we assemble a sample of more than 200,000 distinct foregroun...
Article
We present new measurements of the spatial distribution and kinematics of neutral hydrogen in the circumgalactic and intergalactic medium surrounding star-forming galaxies at z ~ 2. Using the spectra of ~ 3000 galaxies with redshifts ± 0.4 from the Keck Baryonic Structure Survey (KBSS), we assemble a sample of more than 200,000 distinct foreground-...
Article
Full-text available
We present results of a deep spectroscopic survey quantifying the statistics of the escape of ionizing radiation from star-forming galaxies at z ~ 3. We measure the ratio of ionizing to non-ionizing UV flux density , where f 900 is the mean flux density evaluated over the range [880, 910] Å. We quantify the emergent ratio of ionizing to non-ionizin...
Conference Paper
We present a new automated photometric pipeline optimized for time-series photometry that includes a real-time data streaming service. An observer using this resource can automatically stream photometric data over the Internet. Other observers can then monitor the data stream in real time and make an informed decision whether to perform complementa...
Article
We use a large sample of galaxies at z~3 to establish a relationship between reddening, neutral gas covering fraction (fcov(HI)), and the escape of ionizing photons at high redshift. Our sample includes 933 galaxies at z~3, 121 of which have very deep spectroscopic observations (>7 hrs) in the rest-UV (lambda=850-1300 A) with Keck/LRIS. Based on th...
Article
We present the first measurements of the shape of the far-ultraviolet (far-UV; lambda=950-1500 A) dust attenuation curve at high redshift (z~3). Our analysis employs rest-frame UV spectra of 933 galaxies at z~3, 121 of which have very deep spectroscopic observations (>7 hrs) at lambda=850-1300 A, with the Low Resolution Imaging Spectrograph on the...
Article
We present observations of Q1549-C25, an ~L* star-forming galaxy at z=3.15 for which Lyman-continuum (LyC) radiation is significantly detected in deep Keck/LRIS spectroscopy. We find no evidence for contamination from a lower-redshift interloper close to the line of sight in the high signal-to-noise spectrum of Q1549-C25. Furthermore, the morpholog...
Article
Full-text available
We study the Lyα profiles of 36 spectroscopically detected Lyα-emitters (LAEs) at z ~ 2-3, using Keck MOSFIRE to measure systemic redshifts and velocity dispersions from rest-frame optical nebular emission lines. The sample has a median optical magnitude , and ranges from to , corresponding to rest-frame UV absolute magnitudes M UV –22 to M UV > –1...
Article
Full-text available
We study the Lya profiles of 36 Lya-emitters (LAEs) at z~2-3, taking advantage of the sensitivity and efficiency of Keck MOSFIRE to measure systemic redshifts from rest-frame optical nebular emission lines. The galaxies were selected via narrowband imaging of their Lya emission, and have spectroscopic measurements of their Lya profiles from Keck LR...
Article
Full-text available
It has been claimed that the nova-like cataclysmic variable (CV) AE Aquarii (AE Aqr) is a very-high-energy (VHE, $E>$100 GeV) source both on observational and theoretical grounds. We aim to search for VHE gamma-ray emission from AE Aqr during different states of the source at several wavelengths to confirm or rule out previous claims of detection o...
Article
Full-text available
We report on observations of the nova-like cataclysmic variable AE Aqr performed by MAGIC. The observations were part of a quasi-simultaneous multi-wavelength campaign carried out between 2012 May and June covering the optical, UV, X-ray and gamma-ray ranges. MAGIC conducted the campaign and observed the source during 12 hours. The other instrument...
Article
Full-text available
Astronomical Station Vidojevica *http://vidojevica.aob.rs/) is located on Mt.~Vidojevica near Prokuplje, Serbia. The equipment for measuring astro-climate conditions was installed in November 2010. The main characteristics of All-sky Camera, Weather Station and Seeing Monitor are presented. In addition, some preliminary results obtained using the i...
Article
The timing and duration of the reionization epoch is crucial to the emergence and evolution of structure in the universe. The relative roles that star-forming galaxies, active galactic nuclei and quasars play in contributing to the metagalactic ionizing background across cosmic time remains uncertain. Deep quasar counts provide insights into their...
Article
Full-text available
We present results from the Keck Baryonic Structure Survey (KBSS), a unique spectroscopic survey designed to explore the connection between galaxies and intergalactic baryons. The KBSS is optimized for the redshift range z ~ 2-3, combining S/N ~ 100 Keck/HIRES spectra of 15 hyperluminous QSOs with densely sampled galaxy redshift surveys surrounding...
Article
Full-text available
Extended nebulae of Ly-alpha emission ("Ly-alpha blobs") are known to be associated with overdense regions at high redshift. Here we present six large Ly-alpha blobs in a previously known protocluster with galaxy overdensity delta ~ 7 at z = 2.3; this is the richest field of giant Ly-alpha blobs detected to date. The blobs have linear sizes >~100 k...
Article
Full-text available
Using a sample of 92 UV continuum-selected, spectroscopically identified galaxies with z = 2.65, all of which have been imaged in the Lyα line with extremely deep narrow-band imaging, we examine galaxy Lyα emission profiles to very faint surface brightness limits. The galaxy sample is representative of spectroscopic samples of Lyman break galaxies...
Article
Full-text available
Using a sample of 92 UV continuum-selected, spectroscopically identified galaxies with = 2.65, all of which have been imaged in the Ly-a line with extremely deep narrow-band imaging, we examine galaxy Ly-a emission profiles to very faint surface brightness limits. The galaxies are representative of spectroscopic samples of LBGs at similar redshifts...
Article
Full-text available
We present new results on the kinematics and spatial distribution of metal-enriched gas within ~125 kpc of star-forming ("Lyman break") galaxies at redshifts 2 z 3. In particular, we focus on constraints provided by the rest-frame far-ultraviolet (far-UV) spectra of faint galaxies, and demonstrate how galaxy spectra can be used to obtain key spatia...
Article
We present the results of spectroscopic, narrow-band and X-ray observations of a z=2.30 protocluster in the field of the QSO HS 1700+643. Using a sample of BX/MD galaxies, which are selected to be at z~2.2-2.7 by their rest-frame ultraviolet colours, we find that there are 5 protocluster AGN which have been identified by characteristic emission-lin...
Article
Full-text available
We present new results on the kinematics and spatial distribution of metal-enriched gas within 125 kpc (physical) of Lyman Break galaxies at redshifts z~2-3. In particular, we demonstrate how rest-UV galaxy spectra can be used to obtain key spatial and spectral information more efficiently than possible with QSO sightlines. After recalibrating the...
Article
Full-text available
We present the results of a photometric and spectroscopic survey of 321 Lyman break galaxies (LBGs) at z~ 3 to investigate systematically the relationship between Lyα emission and stellar populations. Lyα equivalent widths (W Lyα) were calculated from rest-frame UV spectroscopy and optical/near-infrared/Spitzer photometry was used in population syn...
Article
Full-text available
The evolution of the quasar luminosity function (QLF) is one of the basic cosmological measures providing insight into structure formation and mass assembly in the universe. We have conducted a spectroscopic survey to find faint quasars (–26.0 < M 1450 < –22.0) at redshifts z = 3.8-5.2 in order to measure the faint end of the QLF at these early tim...
Article
In this thesis we present two studies of star-forming galaxies at z ≈2-3 based on deep spectroscopic and narrow band imaging observations. The first study addresses pressing questions regarding the nature of galaxies with significant escaping Lyman continuum radiation. Our second study investigates the nature of spatially extended Lyman alpha emis...
Article
Full-text available
We present the results of a photometric and spectroscopic survey of 321 Lyman break galaxies (LBGs) at z ~ 3 to investigate systematically the relationship between Lya emission and stellar populations. Lya equivalent widths (EW) were calculated from rest-frame UV spectroscopy and optical/near-infrared/Spitzer photometry was used in population synth...
Article
We report on the direct spectroscopic observations of escaping Lyman continuum radiation in individual galaxy spectra drawn from a sample of rest-UV selected (Lyman Break) galaxies at z 3. The fraction of UV photons which manage to escape from galaxies at high redshift is a key parameter required for our understanding of re-ionization and the physi...
Article
Full-text available
We report the discovery of two low-luminosity quasars at z ~ 4, both of which show prominent N iv] λ1486 emission. This line is extremely rare in quasar spectra at any redshift; detecting it in two of a sample of 23 objects (i.e., ~9% of the sample) is intriguing and is likely due to the low-luminosity, high-redshift quasar sample we are studying....
Article
We propose Spitzer IRAC (3.6/5.8 micron) and MIPS (24 micron) observations in the fields of two very bright QSOs, HS1549+1933 (z=2.844) and Q2343+1225 (z=2.574), in which we have been conducting intensive spectroscopic surveys of galaxies and AGN in the redshift range 1.5
Article
We have performed high S/N, near-IR (J and Ks bands) photometry of a sample of 35 PSS quasars at redshifts z ˜ 4.0 - 4.5. Using these measurements we have derived precise power-law slopes for their restframe UV/optical continuum emission. The observed spectral index distribution has a mean value alpha = -0.49, and a fairly wide dispersion, with a G...
Article
We obtained IR IDs and spectroscopy for a sample of steep-spectrum (alpha < -1.3), compact (theta 5 - 7. Therefore, we find that the low-frequency radio sky has a diverse, rich, and interesting phenomenology, with a great scientific promise for the future instruments and surveys in this wavelength regime. This work was supported in part by the NSF...
Article
Full-text available
One of the new frontiers of astronomical research is the exploration of time variability on the sky at different wavelengths and flux levels. We have carried out a pilot project using DPOSS data to study strong variables and transients, and are now extending it to the new Palomar-QUEST synoptic sky survey. We report on our early findings and outlin...
Article
Full-text available
We present observations of an optically faint quasar, RD J114816.2+525339 (hereafter RD J1148+5253), discovered from deep multicolor observations of the field around the z=6.42 quasar SDSS J1148+5251. The two quasars have a projected separation of 109" and both are outliers in r-z versus z-J color-color space. Keck spectroscopy reveals RD J1148+525...
Article
Observations of QSOs at z ∼ 5.7–6.4 show the appearance of Gunn–Peterson troughs around z ∼ 6, and a change in the slope of the IGM optical depth τ(z) near z ∼ 5.5. These results are interpreted as a signature of the end of the reionization era, which probably started at considerably higher redshifts. However, there also appears to be a substantial...
Article
Full-text available
Discoveries in astronomy are often made through a systematic exploration of previously poorly covered regions of the observable parameter space [1,2]. In particular, exploration of the time variability on the sky over a broad range of ux levels and wavelengths is rapidly becoming a new frontier of astronomical research [3,4]. Many exciting astrophy...
Article
The Palomar-Quest (PQ) survey is a major, new, digital, synoptic sky survey which uses the new 112-CCD camera at the Palomar 48-inch Samuel Oschin Schmidt telescope. The survey will cover up to 15,000 deg2 in 7 filters, with multiple observations over the time baselines ranging from days to years, ultimately reaching twice the depth of SDSS in coad...
Article
We have initiated a search for quasars in the redshift interval z ˜ 4 - 6.5 using the drift scans obtained as a part of the Palomar-Quest sky survey. The scans are obtained in Cousins UBRI and SDSS r'i'z'z' bands, with two passes with each filter set over declination strips 4.6 deg wide. Coadded data reach the depth of the SDSS. The anticipated sky...
Article
The Palomar-QUEST large-area camera is a 112-CCD mosaic built by the physics departments at Yale and Indiana Universities and mounted on the California Institute of Technology's 1.2-m Oschin Schmidt at Palomar Observatory. Each individual CCD is a thinned, back-illuminated device with 2400 x 600 13-u pixels yielding a mosaic with 16800 x 9600 pixel...
Article
The Palomar-QUEST Variability Survey is now in routine data taking mode using the 1.3m Oschin Schmidt Telescope at Palomar Observatory with the 112 CCD Large Area QUEST Camera. Data are taken in the drift scan mode 10 to 12 nights each month, producing of the order of 50 gigabytes of data during a clear night, covering about 500 square degrees of s...
Article
Exploration of the time domain is rapidly becoming one of the most exciting areas of astronomy. The Palomar-Quest synoptic sky survey has recently started producing a steady stream of data. In driftscan mode the survey covers Declination strips 4.6 deg wide, between -25 and +30 deg, at least twice in each of the two filter sets, one Johnson-Cousin'...
Article
Full-text available
The challenge in searching for non-radio-pulsing isolated neutron stars (INSs) is in excluding association with objects in the very large error boxes (~13", 1 sigma radius) typical of sources from the largest X-ray all-sky survey, the ROSAT All-Sky-Survey/Bright Source Catalog (RASS/BSC). We search for candidate INSs using statistical analysis of o...
Article
Massive host galaxies of the first luminous quasars should be still undergoing a considerable cosmological infall of the neutral IGM. This process may be observable as a distinct spectroscopic signature in the blue wing of their Lyalpha line, as predicted by Barkana & Loeb (2002). We report on a search for such and effect and its possible redshift...
Article
We present results of the analysis of high-S/N, medium-resolution spectra of 4 SDSS QSOs at z ~ 5.73 - 6.28, obtained with the ESI instrument at the WMKO Keck-II telescope. The spectra show a considerable variation in the optical depth as a function of redshift at z > 5. A clumpy and gradual transition to a fully reionized IGM is generically expect...
Article
The Palomar-QUEST (PQ) sky survey covers 15,000 sq.deg. on the sky, between Declinations -25 and +25 deg, in multiple passes, in UBIR or riz filters. The survey has been operational for over 2 years, with over 10 TB of data in hand. The synoptic nature of the data as well as stacking images belonging to the same part of the sky lends itself to a va...

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Project (1)
Project
real-time photometry pipeline with data broadcast