@article{2496, abstract = {Glutamate is one candidate for the neurotransmitters and/or neuromodulators involved in taste signaling in taste buds. Group II metabotropic glutamate receptors (mGluRs: mGluR2 and mGluR3) are known to function as presynaptic receptors that regulate the release of glutamate and/or other neurotransmitters in the central nervous system. Group II mGluRs are negatively linked to adenylyl cyclase through Gαi subunits and thereby reduce the turnover of cAMP. In rat taste tissues, a subset of adenylyl-cyclase-8-expressing taste cells coexpress the Gαi subunits gustducin and Gαi2. However, the expression patterns of group II mGluRs in rat taste tissues have not yet been elucidated. We have therefore examined the expression patterns of mGluR2, mGluR3, and gustducin in rat gustatory tissues. Reverse transcription/polymerase chain reaction assays have revealed that mGluR2 and mGluR3 mRNAs are expressed in the circumvallate papillae. In situ hybridization analyses have detected positive signals for mGluR2 and mGluR3 mRNAs only in the circumvallate taste buds. Among the fungiform, foliate, and circumvallate papillae, an antibody against mGluR2/3 labels a subset of taste bud cells and nerve fibers immediately beneath the taste lingual epithelium. Double-labeling experiments have demonstrated that mGluR2/3-positive cells coexpress gustducin. These results indicate that mGluR2 and mGluR3 are coupled to Gαi subunits and play roles in glutamate-mediated signaling in taste transductions.}, author = {Toyono, Takashi and Kataoka, Shinji and Seta, Yuji and Ryuichi Shigemoto and Toyoshima, Kuniaki}, journal = {Cell and Tissue Research}, number = {1}, pages = {57 -- 63}, publisher = {Springer}, title = {{Expression of group II metabotropic glutamate receptors in rat gustatory papillae}}, doi = {10.1007/s00441-006-0351-9}, volume = {328}, year = {2007}, } @inbook{167, abstract = {This book contains research articles on Diophantine Geometry, written by participants of a research program held at the Ennio De Giorgi Mathematical Research Center in Pisa, Italy, during the period April – July 2005. The authors are eminent experts in the field. Several subfields of the main topic are presented; the volume thus is particularly useful to get a broad overview of recent research developments.}, author = {Browning, Timothy D and Heath Brown, Roger}, booktitle = {Diophantine Geometry}, editor = {Zannier, Umberto}, pages = {93 -- 100}, publisher = {Edizioni della Normale}, title = {{Simultaneous equal sums of three powers}}, volume = {4}, year = {2007}, } @article{1750, abstract = {The authors investigate the composition profile of SiGe islands after capping with Si to form quantum dots, using a two step etching procedure and atomic force microscopy. Initially, the Si capping layers are removed by etching selectively Si over Ge and then the composition of the disclosed islands is addressed by selectively etching Ge over Si. For samples grown at 580 °C the authors show that even when overgrowth leads to a flat Si surface and the islands undergo strong morphological changes, a Ge-rich core region is still preserved in the dot. At high growth and overgrowth temperatures (740 °C), the experiments show that the newly formed base of the buried islands is more Si rich than their top. Furthermore, the authors find that for the growth conditions used, no lateral motion takes place during capping.}, author = {Georgios Katsaros and Stoffel, Mathieu and Rastelli, Armando and Schmidt, Oliver G and Kern, Klaus and Tersoff, Jerry}, journal = {Applied Physics Letters}, number = {1}, publisher = {American Institute of Physics}, title = {{Three-dimensional isocompositional profiles of buried SiGeSi (001) islands}}, doi = {10.1063/1.2752730}, volume = {91}, year = {2007}, } @article{1762, abstract = {In quantum information science, the phase of a wave function plays an important role in encoding information. Although most experiments in this field rely on dynamic effects to manipulate this information, an alternative approach is to use geometric phase, which has been argued to have potential fault tolerance. We demonstrated the controlled accumulation of a geometric phase, Berry's phase, in a superconducting qubit; we manipulated the qubit geometrically by means of microwave radiation and observed the accumulated phase in an interference experiment. We found excellent agreement with Berry's predictions and also observed a geometry-dependent contribution to dephasing.}, author = {Leek, Peter J and Johannes Fink and Blais, Alexandre and Bianchetti, R and Göppl, M and Gambetta, Jay M and Schuster, David I and Frunzio, Luigi and Schoelkopf, Robert J and Wallraff, Andreas}, journal = {Science}, number = {5858}, pages = {1889 -- 1892}, publisher = {American Association for the Advancement of Science}, title = {{Observation of Berry's phase in a solid-state qubit}}, doi = {10.1126/science.1149858}, volume = {318}, year = {2007}, } @article{17714, abstract = {We investigate the effect of planetary rotation on the transit spectrum of an extrasolar giant planet. During ingress and egress, absorption features arising from the planet's atmosphere are Doppler shifted by of order the planet's rotational velocity (~1-2 km/s) relative to where they would be if the planet were not rotating. We focus in particular on the case of HD209458b, which ought to be at least as good a target as any other known transiting planet. For HD209458b, this shift should give rise to a small net centroid shift of ~60 cm/s on the stellar absorption lines. Using a detailed model of the transmission spectrum due to a rotating star transited by a rotating planet with an isothermal atmosphere, we simulate the effect of the planet's rotation on the shape of the spectral lines, and in particular on the magnitude of their width and centroid shift. We then use this simulation to determine the expected signal-to-noise ratio for distinguishing a rotating from a non-rotating planet, and assess how this S/N scales with various parameters of HD209458b. We find that with a 6 m telescope, an equatorial rotational velocity of ~2 km/s could be detected with a S/N~5 by accumulating the signal over many transits over the course of several years. With a 30 m telescope, the time required to make such a detection reduces to less than 2 months.}, author = {Spiegel, David S. and Haiman, Zoltán and Gaudi, B. Scott}, issn = {0004-637X}, journal = {The Astrophysical Journal}, number = {2}, pages = {1324--1335}, publisher = {American Astronomical Society}, title = {{On constraining a transiting exoplanet’s rotation rate with its transit spectrum}}, doi = {10.1086/521921}, volume = {669}, year = {2007}, } @article{17716, abstract = {Recent observations imply that the observed number counts of Lyα emitters (LAEs) evolved significantly between z= 5.7 and 6.5. It has been suggested that this was due to a rapid evolution in the ionization state, and hence transmission of the intergalactic medium (IGM) which caused Lyα flux from z= 6.5 galaxies to be more strongly suppressed. In this paper, we consider the joint evolution of the Lyα and the ultraviolet luminosity functions (LFs) and show that the IGM transmission evolved between z= 6.5 and 5.7 by a factor 1.1 < R < 1.8 (95 per cent confidence level). This result is insensitive to the underlying model of the Lyα LF (as well as cosmic variance). Using a model for IGM transmission, we find that the evolution of the mean IGM density through cosmic expansion alone may result in a value for the ratio of transmissions as high as R= 1.3. Thus, the existing LFs do not provide evidence for overlap. Furthermore, the constraint R < 1.8 suggests that the Universe at z= 6.5 was more than half-ionized by volume, that is, xi,V > 0.5.}, author = {Dijkstra, M. and Wyithe, J. S. B. and Haiman, Zoltán}, issn = {0035-8711}, journal = {Monthly Notices of the Royal Astronomical Society}, number = {1}, pages = {253--259}, publisher = {Oxford University Press}, title = {{Luminosity functions of Lyα emitting galaxies and cosmic reionization of hydrogen}}, doi = {10.1111/j.1365-2966.2007.11936.x}, volume = {379}, year = {2007}, } @article{17724, abstract = {The continuous improvement in localization errors (sky position and distance) in real time as LISA observes the gradual inspiral of a supermassive black hole (SMBH) binary can be of great help in identifying any prompt electromagnetic counterpart associated with the merger. We develop a new method, based on a Fourier decomposition of the time-dependent, LISA-modulated gravitational-wave signal, to study this intricate problem. The method is faster than standard Monte Carlo simulations by orders of magnitude. By surveying the parameter space of potential LISA sources, we find that counterparts to SMBH binary mergers with total mass M~10^5-10^7 M_Sun and redshifts z<~3 can be localized to within the field of view of astronomical instruments (~deg^2) typically hours to weeks prior to coalescence. This will allow targeted searches for variable electromagnetic counterparts as the merger proceeds, as well as monitoring of the most energetic coalescence phase. A rich set of astrophysical and cosmological applications would emerge from the identification of electromagnetic counterparts to these gravitational-wave standard sirens.}, author = {Kocsis, Bence and Haiman, Zoltán and Menou, Kristen and Frei, Zsolt}, issn = {1550-7998}, journal = {Physical Review D}, number = {2}, publisher = {American Physical Society}, title = {{Premerger localization of gravitational-wave standard sirens with LISA: Harmonic mode decomposition}}, doi = {10.1103/physrevd.76.022003}, volume = {76}, year = {2007}, } @article{17729, abstract = {We make use of hydrodynamical simulations of the intergalactic medium (IGM) to create model quasar absorption spectra. We compare these model spectra with the observed Keck spectra of three z>6.2 quasars with full Gunn-Peterson troughs: SDSS J1148+5251 (z=6.42), SDSS J1030+0524 (z=6.28), and SDSS J1623+3112 (z=6.22). We fit the probability density distributions (PDFs) of the observed Ly alpha optical depths with those generated from the simulation, by exploring a range of values for the size of the quasar's surrounding HII region, R_S, the volume-weighted mean neutral hydrogen fraction in the ambient IGM, x_H, and the quasar's ionizing photon emissivity, N_Q. In order to avoid averaging over possibly large sightline-to-sightline fluctuations in IGM properties, we analyze each observed quasar independently. We find the following results for J1148+5251, J1030+0524, and J1623+3112: The best-fit sizes R_S are 40, 41, and 29 (comoving) Mpc, respectively. These constraints are tight, with only ~ 10% uncertainties, comparable to those caused by redshift--determination errors. The best-fit values of N_Q are 2.1, 1.3, and 0.9 x 10^{57} s^{-1}, respectively, with a factor of ~ 2 uncertainty in each case. Finally, the best--fit values of x_H are 0.16, 1.0, and 1.0, respectively. The uncertainty in the case of J1148+5251 is large, and x_H is not well constrained. However, for both J1030+0524 and J1623+3112, we find a significant lower limit of x_H >~ 0.033. Our method is different from previous analyses of the GP absorption spectra of these quasars, and our results strengthen the evidence that the rapid end--stage of reionization is occurring near z ~ 6.}, author = {Mesinger, Andrei and Haiman, Zoltán}, issn = {0004-637X}, journal = {The Astrophysical Journal}, number = {2}, pages = {923--932}, publisher = {American Astronomical Society}, title = {{Constraints on reionization and Source Properties from the Absorption Spectra of z > 6.2 quasars}}, doi = {10.1086/513688}, volume = {660}, year = {2007}, } @article{17732, abstract = {Energetic feedback processes during the formation of galaxy clusters may have heated and ionized a large fraction of the intergalactic gas in proto-cluster regions. When such a highly ionized hot ``super-bubble'' falls along the sightline to a background quasar, it would be seen as a large void, with little or no absorption, in the Lyman alpha forest. We examine the spectra of 137 quasars in the Sloan Digital Sky Survey, to search for such voids, and find no clear evidence of their existence. The size distribution of voids in the range 5-70 Angstrom (corresponding to physical sizes of approximately 3-35 comoving Mpc/h) is consistent with the standard model for the Lyman alpha forest without additional hot bubbles. We adapt a physical model for HII bubble growth during cosmological reionization (Furlanetto, Zaldarriaga and Hernquist 2004), to describe the expected size-distribution of hot super-bubbles at redshift around z = 3. This model incorporates the conjoining of bubbles around individual neighboring galaxies. Using the non-detection of voids, we find that models in which the volume filling factor of hot bubbles exceeds approximately 20 percent at z=3 can be ruled out, primarily because they overproduce the number of large (40-50 Angstrom) voids. We conclude that any pre-heating mechanism that explains galaxy cluster observations must avoid heating the low-density gas in the proto-cluster regions, either by operating relatively recently (z<3) or by depositing entropy in the high-density regions.}, author = {Shang, Cien and Crotts, Arlin and Haiman, Zoltán}, issn = {0004-637X}, journal = {The Astrophysical Journal}, number = {1}, pages = {136--145}, publisher = {American Astronomical Society}, title = {{Constraints on the abundance of highly ionized protocluster regions from the absence of large voids in the Lyα forest}}, doi = {10.1086/522331}, volume = {671}, year = {2007}, } @article{17738, abstract = {Recent observations reveal that a majority of galaxies contain a central massive object (CMO), either a supermassive black hole (SMBH) or a compact stellar nucleus, regardless of the galaxy mass or morphological type. The masses of these CMOs correlate tightly with those of the host galaxies, MCMO ≈ 0.002Mgal. Several recent studies argue that feedback from black holes can successfully explain the MBH-σ correlation in massive elliptical galaxies that contain SMBHs. However, puzzles remain in spirals or dwarf spheroids that do not appear to have black holes but instead harbor a compact central stellar cluster. Here we use three-dimensional, smoothed particle hydrodynamics simulations of both isolated and merging galaxies to study the formation and evolution of CMOs in bulgeless disk galaxies, and the transition of the CMO-host relations from late-type bulgeless spirals to early-type ellipticals. Our simulations show that the mass of the CMO correlates with that of the host galaxy in both isolated bulgeless spirals and in ellipticals formed through mergers, and that MCMO correlates with the global star formation efficiency in the galaxy. We find that the final mass of the CMO is dominated by the accreted mass, rather than the initial fragment mass, and that both the final accreted CMO mass and the recently formed stellar mass increase monotonically with the total mass of the galaxy. Our results suggest that the observed correlations may be established primarily by the depletion of gas in the central region by accretion and star formation, and may hold for all galaxy types. A systematic search for CMOs in the nuclei of bulgeless disk galaxies would offer a test of this conclusion.}, author = {Li, Yuexing and Haiman, Zoltán and Mac Low, Mordecai‐Mark}, issn = {0004-637X}, journal = {The Astrophysical Journal}, number = {1}, pages = {61--70}, publisher = {American Astronomical Society}, title = {{Correlations between central massive objects and their host galaxies: From bulgeless spirals to ellipticals}}, doi = {10.1086/518398}, volume = {663}, year = {2007}, } @article{17753, abstract = {We use the spectra of 22,000 nearby early-type galaxies from the Sloan Digital Sky Survey (SDSS) to determine the age distribution of these galaxies as a function of their velocity dispersion sigma_v in the range 100 km/s < sigma_v < 280 km/s. We then combine the inferred age-distributions with the local abundance of spheroids, including early-type galaxies and late-type bulges, to predict the evolution of the quasar luminosity function (LF) in the redshift range 0 at fixed sigma_v. These assumptions require that the SMBH remnants of quasars with bolometric luminosity below L_bol=10^{12.5} f_Edd L_sun reside predominantly in bulges of late type galaxies. We find that evolution of the observed quasar LF can be fit over the entire redshift range in this simple model, 0=0.3-0.5. We find no evidence that any of the model parameters evolves with redshift, supporting the strong connection between the formation of stars and nuclear SMBHs in spheroids.}, author = {Haiman, Zoltán and Jimenez, Raul and Bernardi, Mariangela}, issn = {0004-637X}, journal = {The Astrophysical Journal}, number = {2}, pages = {721--730}, publisher = {American Astronomical Society}, title = {{Reconstructing the cosmic evolution of quasars from the age distribution of local early‐type galaxies}}, doi = {10.1086/510840}, volume = {658}, year = {2007}, } @inproceedings{17755, author = {Kocsis, B. and Haiman, Zoltán and Frei, Z.}, booktitle = {ESO Astrophysics Symposia}, isbn = {9783540747123}, location = {Munich, Germany}, pages = {334--336}, publisher = {Springer Berlin Heidelberg}, title = {{Detecting virialization shocks around galaxy clusters through the SZ effect}}, doi = {10.1007/978-3-540-74713-0_77}, year = {2007}, } @article{17768, abstract = {We develop an analytic approach to study inhomogeneous reionization on large scales by solving the equations of ionization balance and radiative transfer to first order in perturbations. Given the spatial distribution and spectrum of the ionizing sources, our formalism can be used to predict the large-scale power spectra of fluctuations in the abundances of H ii, H i and radiation. Our approach avoids common approximations/assumptions in existing analytic methods – for instance, we do not assume a specific ionization topology from the outset; nor do we make a step-function bubble-like approximation to the H ii distribution. Applying our formalism to sources biased according to the Press–Schechter prescription, we find: (1) reionization always proceeds ‘inside–out’, with dense regions more highly ionized, at least on large scales; (2) on sufficiently large scales, H ii, H i and radiation exhibit a scale-independent bias relative to dark matter; (3) the bias is suppressed on scales comparable to or smaller than the mean free path of the ionizing photons; (4) if the ionizing source spectrum is sufficiently soft, the H ii bias closely tracks the source bias for most of the reionization process but drops precipitously after percolation; and (5) if the ionizing source spectrum is sufficiently hard, the H ii bias drops in a more steady fashion throughout the reionization process. The tools developed here will be useful for interpreting future 21-cm, cosmic microwave background and Lyman α forest observations, both to learn about the reionization astrophysics (such as the hardness of the source spectrum and therefore the nature of the ionizing sources) and to possibly extract interesting cosmological information.}, author = {Zhang, J. and Hui, L. and Haiman, Zoltán}, issn = {0035-8711}, journal = {Monthly Notices of the Royal Astronomical Society}, number = {1}, pages = {324--336}, publisher = {Oxford University Press}, title = {{A linear perturbation theory of inhomogeneous reionization}}, doi = {10.1111/j.1365-2966.2006.11311.x}, volume = {375}, year = {2007}, } @article{17783, abstract = {We apply the technique of parameter-splitting to existing cosmological data sets, to check for a generic failure of dark energy models. Given a dark energy parameter, such as the energy density Omega_Lambda or equation of state w, we split it into two meta-parameters with one controlling geometrical distances, and the other controlling the growth of structure. Observational data spanning Type Ia Supernovae, the cosmic microwave background (CMB), galaxy clustering, and weak gravitational lensing statistics are fit without requiring the two meta-parameters to be equal. This technique checks for inconsistency between different data sets, as well as for internal inconsistency within any one data set (e.g., CMB or lensing statistics) that is sensitive to both geometry and growth. We find that the cosmological constant model is consistent with current data. Theories of modified gravity generally predict a relation between growth and geometry that is different from that of general relativity. Parameter-splitting can be viewed as a crude way to parametrize the space of such theories. Our analysis of current data already appears to put sharp limits on these theories: assuming a flat universe, current data constrain the difference Omega_Lambda(geom) - Omega_Lambda(grow) to be -0.0044 +/- 0.0058 (68% C.L.); allowing the equation of state w to vary, the difference w(geom) - w(grow) is constrained to be 0.37 +/- 0.37 (68% C.L.). Interestingly, the region w(grow) > w(geom), which should be generically favored by theories that slow structure formation relative to general relativity, is quite restricted by data already. We find w(grow) < -0.80 at 2 sigma. As an example, the best-fit flat Dvali-Gabadadze-Porrati (DGP) model approximated by our parametrization lies beyond the 3 sigma contour for constraints from all the data sets.}, author = {Wang, Sheng and Hui, Lam and May, Morgan and Haiman, Zoltán}, issn = {1550-7998}, journal = {Physical Review D}, number = {6}, publisher = {American Physical Society}, title = {{Is modified gravity required by observations? An empirical consistency test of dark energy models}}, doi = {10.1103/physrevd.76.063503}, volume = {76}, year = {2007}, } @inproceedings{17784, author = {Gáspár, M.E. and Haiman, Zoltán and Frei, Z.}, booktitle = {ESO Astrophysics Symposia}, isbn = {9783540747123}, location = {Munich, Germany}, publisher = {Springer Berlin Heidelberg}, title = {{Mass function of remnant black holes in nearby galaxies}}, doi = {10.1007/978-3-540-74713-0_31}, year = {2007}, } @article{17785, abstract = {We study the potential of a large future weak-lensing survey to constrain dark energy properties by using both the number counts of detected galaxy clusters (sensitive primarily to density fluctuations on small scales) and tomographic shear-shear correlations (restricted to large scales). We use the Fisher matrix formalism, assume a flat universe and parameterize the equation of state of dark energy by w(a)=w_0+w_a(1-a), to forecast the expected statistical errors from either observable, and from their combination. We show that the covariance between these two observables is small, and argue that therefore they can be regarded as independent constraints. We find that when the number counts and the shear-shear correlations (on angular scales l < 1000) are combined, an LSST (Large Synoptic Survey Telescope)-like survey can yield statistical errors on (Omega_DE, w_0, w_a) as tight as (0.003, 0.03, 0.1). These values are a factor of 2-25 better than using either observable alone. The results are also about a factor of two better than those from combining number counts of galaxy clusters and their power spectrum.}, author = {Fang, Wenjuan and Haiman, Zoltán}, issn = {1550-7998}, journal = {Physical Review D}, number = {4}, publisher = {American Physical Society}, title = {{Constraining dark energy by combining cluster counts and shear-shear correlations in a weak lensing survey}}, doi = {10.1103/physrevd.75.043010}, volume = {75}, year = {2007}, } @article{17791, abstract = {We consider the pumping of the 63.2 μm fine-structure line of neutral O I in the high-redshift intergalactic medium (IGM), in analogy with the Wouthuysen-Field effect for the 21 cm line of cosmic H I. We show that the soft UV background at ~1300 Å can affect the population levels, and if a significant fraction of the IGM volume is filled with "fossil H II regions" containing neutral O I, then this can produce a nonnegligible spectral distortion in the cosmic microwave background (CMB). O I from redshift z is seen in emission at (1 + z)63.2 μm, and in the range 7 < z < 10 produces a mean spectral distortion of the CMB with y = (10^-9 to 3 × 10^-8)(Z/10^-3 Z☉)(IUV), where Z is the mean metallicity of the IGM and IUV is the UV background at 1300 Å in units of 10^-20 ergs s-1 Hz^-1 cm-2 sr^-1. A measurement of this signature can trace the metallicity at the end of the dark ages, prior to the completion of cosmic reionization, and is complementary to cosmological 21 cm studies. While future CMB experiments such as Planck could constrain the metallicity to the 10^-2 Z☉ level, specifically designed experiments could potentially achieve a detection.}, author = {Hernández-Monteagudo, Carlos and Haiman, Zoltán and Jimenez, Raul and Verde, Licia}, issn = {0004-637X}, journal = {The Astrophysical Journal}, number = {2}, pages = {L85--L88}, publisher = {American Astronomical Society}, title = {{Oxygen pumping: Probing intergalactic metals at the epoch of reionization}}, doi = {10.1086/518090}, volume = {660}, year = {2007}, } @article{17793, abstract = {We use the spectra of ~22,000 early-type galaxies, selected from the Sloan Digital Sky Survey, to infer the ages, metallicities, and star formation histories of these galaxies. We find clear evidence of "downsizing," i.e., that galaxies with larger velocity dispersion have older stellar populations. In particular, we find that most early-type galaxies with velocity dispersion exceeding 200 km s-1 formed more than 90% of their current stellar mass at redshift z > 2.5. Therefore, star formation was suppressed around this redshift. We also show that chemical enrichment was rapid, lasting 1-2 Gyr, and find evidence that [Fe/H] is subsolar. We study the robustness of these results by comparing three different approaches: (1) using Lick absorption line indices, (2) fitting a single-burst stellar population model to the whole spectrum (lines and continuum), and (3) reconstructing the star formation and metallicity histories in multiple age bins, providing a method to measure mass-weighted ages and metallicities. We find good agreement between the luminosity-weighted ages and metallicities computed with these three methods.}, author = {Jimenez, Raul and Bernardi, Mariangela and Haiman, Zoltán and Panter, Ben and Heavens, Alan F.}, issn = {0004-637X}, journal = {The Astrophysical Journal}, number = {2}, pages = {947--951}, publisher = {American Astronomical Society}, title = {{The ages, metallicities, and star formation histories of early‐type galaxies in the SDSS}}, doi = {10.1086/521323}, volume = {669}, year = {2007}, } @inproceedings{17795, abstract = {The gravitational waves (GWs) emitted during the coalescence of supermassive black holes (SMBHs) will be detectable with the future Laser Interferometric Space Antenna (LISA). The direction and distance can be determined from the accumulated GW signal with a precision that increases rapidly in the final stages of the inspiral. We find that for M = (105 − 107)M⊙ near z = 1 the angular uncertainty decreases under 1ˆ at least several hours before the plunge, allowing a targeted electromagnetic (EM) observation of the final stages of the merger with a wide field instrument. We then calculate the size of the final, three dimensional error volume. Under the plausible assumption that SMBH-SMBH mergers are accompanied by gas accretion leading to Eddington-limited quasar activity, we find that many cases this error volume will contain at most a single quasar for M = (105 − 107) M⊙ near z = 1. This will allow a straightforward test of the hypothesis that GW events are accompanied by bright quasar activity. The identification and observation of counterparts would allow unprecedented tests of the physics of MBH accretion, such as precision–measurements of the Eddington ratio. They would clarify the role of gas as a catalyst in SMBH coalescences, and would also offer an alternative method to constrain cosmological parameters.}, author = {Kocsis, B. and Frei, Z. and Haiman, Zoltán and Menou, K.}, booktitle = {Proceedings of the 2005 MPE/USM/MPA/ESO Joint Astronomy Conference}, isbn = {9783540747123}, location = {Munich, Germany}, pages = {82--86}, publisher = {Springer Nature}, title = {{Finding the electromagnetic counterparts of standard sirens}}, doi = {10.1007/978-3-540-74713-0_18}, year = {2007}, } @article{7704, abstract = {Gradients of axon guidance molecules instruct the formation of continuous neural maps, such as the retinotopic map in the vertebrate visual system. Here we show that molecular gradients can also instruct the formation of a discrete neural map. In the fly olfactory system, axons of 50 classes of olfactory receptor neurons (ORNs) and dendrites of 50 classes of projection neurons (PNs) form one-to-one connections at discrete units called glomeruli. We provide expression, loss- and gain-of-function data to demonstrate that the levels of transmembrane Semaphorin-1a (Sema-1a), acting cell-autonomously as a receptor or part of a receptor complex, direct the dendritic targeting of PNs along the dorsolateral to ventromedial axis of the antennal lobe. Sema-1a also regulates PN axon targeting in higher olfactory centers. Thus, graded expression of Sema-1a contributes to connection specificity from ORNs to PNs and then to higher brain centers, ensuring proper representation of olfactory information in the brain.}, author = {Komiyama, Takaki and Sweeney, Lora Beatrice Jaeger and Schuldiner, Oren and Garcia, K. Christopher and Luo, Liqun}, issn = {0092-8674}, journal = {Cell}, number = {2}, pages = {399--410}, publisher = {Elsevier}, title = {{Graded expression of semaphorin-1a cell-autonomously directs dendritic targeting of olfactory projection neurons}}, doi = {10.1016/j.cell.2006.12.028}, volume = {128}, year = {2007}, }