Gravitational Magnification of Population III Supernovae in Hierarchical Cosmological Models: Next Generation Space Telescope Perspectives

Marri, S.; Ferrara, Andrea

doi:10.1086/306475

Cited by 23 publications

(28 citation statements)

References 67 publications

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“…Very rare and unique events, such as lensed supernovae (e.g. Marri & Ferrara 1998;Marri et al 2000), or a tidal disruption of a star by a BH (cf. Stern et al 2004) cannot be excluded either, but again such events are not expected to dominate the sample.…”

Section: C2 Transient Objectsmentioning

confidence: 99%

Constraining the population of $6 \la {z} \la 10$ star-forming galaxies with deep near-IR images of lensing clusters

Richard¹,

Pelló²,

Schaerer

et al. 2006

A&A

227

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We present the first results of our deep survey of lensing clusters aimed at constraining the abundance of star-forming galaxies at z ∼ 6−10, using lensing magnification to improve the search efficiency and subsequent spectroscopic studies. Deep near-IR photometry of two lensing clusters (A1835 and AC114) was obtained with ISAAC/VLT. These images, combined with existing data in the optical bands including HST images, were used to select very high redshift candidates at z > ∼ 6 among the optical-dropouts. Photometric selection criteria have been defined based on the well-proven dropout technique, specifically tuned to target star-forming galaxies in this redshift domain. We have identified 18(8) first and second-category optical dropouts in A1835 (AC114), detected in more than one filter up to H (Vega) ∼ 23.8 (AB ∼ 25.2, uncorrected for lensing). Among them, 8(5) exhibit homogeneous SEDs compatible with star-forming galaxies at z > ∼ 6, and 5(1) are more likely intermediate-redshift EROs based on luminosity considerations. We have also identified a number of fainter sources in these fields fulfilling our photometric selection and located around the critical lines. We use all these data to make a first attempt at constraining the density of star-forming galaxies present at 6 < ∼ z < ∼ 10 using lensing clusters. Magnification effects and sample incompleteness are addressed through a careful modeling of the lensing clusters. A correction was also introduced to account for the expected fraction of false-positive detections among this photometric sample. It appears that the number of candidates found in these lensing fields, corrected for magnification, incompleteness and false-positive detections, is higher than the one achieved in blank fields with similar photometric depth in the near-IR. The luminosity function derived for z > ∼ 6 candidates appears compatible with that of LBGs at z 3, without any renormalization. The turnover observed by Bouwens et al. (2005) towards the bright end relative to the z ∼ 3 LF is not observed in this sample. Also the upper limit for the UV SFR density at z ∼ 6−10, integrated down to L 1500 = 0.3 L * z=3 , of ρ = 7.4 × 10 −2 M yr −1 Mpc −3 is compatible with the usual values derived at z 5−6, but higher than the estimates obtained in the NICMOS Ultra Deep Field (UDF). The same holds for the upper limit of the SFR density in the z 8−10 interval (ρ = 1.1 × 10 −1 ). This systematic trend towards the bright end of the LF with respect to blank fields could be due to field-to-field variance, a positive magnification bias from intermediate-redshift EROs, and/or residual contamination. Given the low S/N ratio of the high-z candidates, and the large correction factors applied to this sample, increasing the number of blank and lensing fields with ultra-deep near-IR photometry is essential to obtain more accurate constraints on the abundance of z > ∼ 6 galaxies.

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Section: C2 Transient Objectsmentioning

confidence: 99%

Constraining the population of $6 \la {z} \la 10$ star-forming galaxies with deep near-IR images of lensing clusters

Richard¹,

Pelló²,

Schaerer

et al. 2006

A&A

227

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“…As an example, we consider the so-called Standard Cold Dark Matter (SCDM), with Ω M = 1, Ω Λ = 0, and h = 0.5; the power spectrum |δ k | 2 is taken from Efstathiou et al (1992), normalized to the present-day abundance of rich clusters (σ 8 = 0.6; Eke, Cole, & Frenk 1996). To calculate the number density of dark matter halos as a function of redshift we use the Press & Schechter (1974, hereafter PS) formalism; this technique is widely used in semi-analytical models of galaxy formation and gravitational lensing (White & Frenk 1991, Kauffman 1995, Ciardi & Ferrara 1997, Baugh et al 1998, Guiderdoni et al 1998, Marri & Ferrara 1998 and it has been shown to be in surprisingly good agreement with the results from N-body numerical simulations. Given a power spectrum |δ k | 2 , one can write the Gaussian variance of the fluctuations on the mass scale M :…”

Section: Predictions For Cdm Modelsmentioning

confidence: 99%

Mixing metals in the early Universe

Ferrara

Pettini

Shchekinov

2000

Monthly Notices of the Royal Astronomical Society

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We investigate the evolution of the metallicity of the intergalactic medium (IGM) with particular emphasis on its spatial distribution. We propose that metal enrichment occurs as a two step process. First, supernova (SN) explosions eject metals into relatively small regions confined to the surroundings of star-forming galaxies. From a comprehensive treatment of blowout we show that SNae by themselves fail by more than one order of magnitude to distribute the products of stellar nucleosynthesis over volumes large enough to pollute the whole IGM to the metallicity levels observed. Thus, a additional (but as yet unknown) physical mechanism must be invoked to mix the metals on scales comparable to the mean distance between the galaxies which are most efficient pollutants. From this simple hypothesis we derive a number of testable predictions for the evolution of the IGM metallicity. Specifically, we find that: (i) the fraction of metals ejected over the star formation history of the universe is about 50% at z = 0; that is, approximately half of the metals today are found in the IGM; (ii) if the ejected metals were homogeneously mixed with the baryons in the universe, the average IGM metallicity would be Z = Ω ej Z /Ω b ≃ 1/25Z ⊙ at z = 3. However, due to spatial inhomogeneities, the mean of the distribution of metallicities in the diffusive zones has a wide (more than 2 orders of magnitude) spread around this value; (iii) if metals become more uniformly distributed at z < ∼ 1, as assumed, at z = 0 the metallicity of the IGM is narrowly confined within the range Z ≈ 0.1 ± 0.03Z ⊙ . Finally, we point out that our results can account for the observed metal content of the intracluster medium.

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“…We Ðnd that, even for sources at these early epochs, the optical depth for strong lensing is small, q B 0.008 for and SCDM. z s \ 7 Marri & Ferrara (1998) have recently explored in details the observational perspectives for Population III SNe detection with the NGST when gravitational magniÐcation is taken into account. They computed lensing frequencies and magniÐcation maps using a ray-shooting numerical technique and assuming pointlike lenses.…”

Section: Discussionmentioning

confidence: 99%

“…It has recently been realized by many authors (Kolatt & Bartelmann 1998 ;Metcalf 1999 ;Holz 1998 ;Marri & Ferrara 1998 ;Wang 2000 ; see also Linder, Schneider, & Wagoner 1988) that gravitational lensing of distant supernovae (SNe) may provide a new tool for doing cosmology. When corrected for light and color curve shapes, Type Ia SNe can be calibrated to be excellent standard candles, with a brightness at maximum B light of M V \ [19.4^0.15 mag (Riess, Press, & Kirshner 1996 ;Hamuy et al 1996).…”

Section: Introductionmentioning

confidence: 99%

Untitled

2000

ApJ

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Ongoing searches for supernovae (SNe) at cosmological distances have recently started to provide large numbers of events with measured redshifts and apparent brightnesses. Compared to quasars or galaxies, Type Ia SNe represent a population of sources with well-known intrinsic properties and could be used to detect gravitational lensing even in the absence of multiple or highly distorted images. We investigate the lensing e †ect of background SNe due to mass condensations in three popular cold dark matter cosmologies ("CDM, OCDM, and SCDM) and compute lensing frequencies, rates of SN explosions, and distributions of arrival-time di †erences and image separations. If dark halos approximate singular isothermal spheres on galaxy scales and Navarro-Frenk-White proÐles on group/cluster scales, and are distributed in mass according to the Press-Schechter theory, then about one of every 12 SNe at z D 1 will be magniÐed by *m º 0.1 mag (SCDM). The detection rate of SNe Ia with magniÐcation *m º 0.3 is estimated to be of the order of a few events yr~1 deg~2 at maximum B light and 100 times I AB ¹ 25, smaller than the total rate expected at these magnitude levels. In the Ðeld, events magniÐed by more than 0.75 mag are 7 times less frequent ; about one-Ðfth of them give rise to observable multiple images. While the time delay between the images is shorter than 3 days in D25% of the cases (shorter than 30 days in 50%) (SCDM), a serious bias against the detection of small-separation events in ground-based surveys is caused by the luminosity of the foreground lensing galaxy. Because of the Ñat K-correction and wide luminosity function, Type II SNe dominate the number counts at and have the I AB [ 25 largest fraction of lensed objects. The optimal survey sensitivity for Type Ia SNe magniÐed by *m º 0.75 mag is MagniÐcation bias increases their incidence by a factor of 50 in samples with I AB B 23. I AB ¹ 22, dropping to a factor of 3.5 at 24 mag. At faint magnitudes, the enhancement is larger for SNe II.

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Gravitational Magnification of Population III Supernovae in Hierarchical Cosmological Models: Next Generation Space Telescope Perspectives

Cited by 23 publications

References 67 publications

Constraining the population of $6 \la {z} \la 10$ star-forming galaxies with deep near-IR images of lensing clusters

Constraining the population of $6 \la {z} \la 10$ star-forming galaxies with deep near-IR images of lensing clusters

Mixing metals in the early Universe

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