Related papers: Extremely Red Objects: an X-ray dichotomy

Extremely Red Objects (EROs, R-K>5) constitute a heterogenous class of extragalactic sources including high redshift elliptical galaxies, dusty star-forming systems and heavily obscured AGNs. Hard X-ray observations provide an unique and…

Understanding the nature of Extremely Red Objects [EROs; (I-K)>=4] is one of the most challenging issues in observational cosmology. Here we report on the X-ray constraints provided by the 2 Ms Chandra Deep Field-North Survey (CDF-N). X-ray…

We present the X-ray properties of the extremely red objects (ERO) population observed by Chandra with three partially overlapping pointings (up to ~90 ks) over an area of ~500 arcmin^2, down to a 0.5-8 keV flux limit of ~10-15 erg cm-2…

We identify a deep sample of 198 extremely red objects (EROs) in (50.4 sq. arcmin of) the Chandra Deep Field South, selected as I-K>3.92 galaxies to a limit K=22. The ERO number counts remain well below the predictions for pure luminosity…

We present a multi-wavelength study of Extremely Red Objects (EROs) employing deep RIzJHK photometry of a 8.5'x8.5' region to identify 68 EROs with R-K>5.3 and K<20.5 (5-sigma). This is combined with an extremely deep 1.4-GHz radio map…

We present the results of sub-mm, mm (850 um, 450 um and 1250 um) and radio (1.4 and 4.8 GHz) continuum observations of a sample of 27 K-selected Extremely Red Objects, or EROs, (14 of which form a complete sample with K < 20 and I-K > 5)…

In this paper we present a quantitative study of the classification of Extremely Red Objects (EROs). The analysis is based on the multi-band spatial- and ground-based observations (HST/ACS-$BViz$, HST/NICMOS-$JH$, VLT-$JHK$) in the Hubble…

We present near-infrared VLT-UT1+ISAAC spectroscopy of a sample of 9 extremely red galaxies (ERGs) with R-K>5 and K<19.0. Neither strong emission lines (F_lim<1-5 10^{-16} erg s^{-1}cm^{-2}) nor continuum breaks are detected. From…

We construct a sample of extremely red objects (EROs) within the UKIDSS Ultra Deep Survey by combining the Early Data Release with optical data from the Subaru/XMM-Newton Deep Field. We find a total of 3715 objects over 2013 sq. arcmin with…

We present VLT near-IR spectroscopic observations of three X-ray sources characterized by extremely high X-ray-to-optical ratios (X/O>40), extremely red colors (6.3<R-K<7.4, i.e. EROs) and bright infrared magnitudes (17.6<K<18.3). These…

We report on the X-ray, optical, near-infrared, submillimetre and radio properties of five Extremely Red Objects (EROs) selected at X-ray wavelengths by XMM-Newton in the Lockman Hole field. They all have enough counts in the X-ray band to…

We present preliminary results of a 25 ks XMM-Newton observation of the largest sample of Extremely Red Objects (EROs) available to date (about 450 sources), selected in a contiguous area of 700 arcmin^2 (Daddi et al. 2000). Five of the 36…

We briefly discuss our survey of Extremely Red Objects (EROs) with HST/NICMOS and deep ground-based images and summarize its results. We use the high-resolution NICMOS images to sub-divide EROs into morphological classes, tentatively…

We study 87 Extremely Red Objects (EROs), selected both to have color redder than R-[3.6] = 4.0, and to have confirmed spectroscopic redshifts. Together, these two constraints result in this sample populating a fairly narrow redshift range…

We have discovered a concentration of extremely red objects (EROs; R-K>6) in the field of the z=2.69 quasar QSO 1213-0017 (UM 485), which is significantly overabundant compared to the field ERO surface density. The optical/near-IR colors of…

We present a method based on two broad-band colors to investigate the nature of the Extremely Red Objects (EROs), i.e., the galaxies selected to have very red optical-to-infrared colors. Dusty starburst and old ellipticals at redshifts…

The multi-wavelength properties of Very Red Objects (VROs; I-K>=4) are largely unknown as many of these sources are optically faint (I>=24) and undetected at most wavelengths. Here we provide constraints on the X-ray properties of VROs…

We present the results of a deep (about 80 ks) XMM-Newton survey of the largest sample of near-infrared selected Extremely Red Objects (R-K>5) available to date to K_S< 19.2. At the relatively bright X-ray fluxes (F_{2-10 keV}> 4x10^{-15}…

[abridged] The properties of galaxies with the reddest observed R-K colors (Extremely Red Objects, EROs), including their apparent division into passive and obscured active objects with roughly similar number densities, are a known…

Extremely Red Objects (EROs) offer a window to the universe at z~1 analogous to that provided by the Lyman Break galaxies at z=3. Passive evolution and hierarchical galaxy formation models make very distinct predictions for the K (2.2um)…