696 research outputs found
Flux and Photon Spectral Index Distributions of Fermi-LAT Blazars And Contribution To The Extragalactic Gamma-ray Background
We present a determination of the distributions of photon spectral index and
gamma-ray flux - the so called LogN-LogS relation - for the 352 blazars
detected with a greater than approximately seven sigma detection threshold and
located above +/- 20 degrees Galactic latitude by the Large Area Telescope of
the Fermi Gamma-ray Space Telescope in its first year catalog. Because the flux
detection threshold depends on the photon index, the observed raw distributions
do not provide the true LogN-LogS counts or the true distribution of the photon
index. We use the non-parametric methods developed by Efron and Petrosian to
reconstruct the intrinsic distributions from the observed ones which account
for the data truncations introduced by observational bias and includes the
effects of the possible correlation between the two variables. We demonstrate
the robustness of our procedures using a simulated data set of blazars and then
apply these to the real data and find that for the population as a whole the
intrinsic flux distribution can be represented by a broken power law with high
and low indexes of -2.37 +/- 0.13 and -1.70 +/- 0.26, respectively, and the
intrinsic photon index distribution can be represented by a Gaussian with mean
of 2.41 +/- 0.13 and width of 0.25 +/- 0.03. We also find the intrinsic
distributions for the sub-populations of BL Lac and FSRQs type blazars
separately. We then calculate the contribution of Fermi blazars to the diffuse
extragalactic gamma-ray background radiation. Under the assumption that the
flux distribution of blazars continues to arbitrarily low fluxes, we calculate
the best fit contribution of all blazars to the total extragalactic gamma-ray
output to be 60%, with a large uncertainty.Comment: 13 pages, 13 figures, 2 tables, updated to published version with
additional figure
Gamma-ray Luminosity and Photon Index Evolution of FSRQ Blazars and Contribution to the Gamma-ray Background
We present the redshift evolutions and distributions of the gamma-ray
luminosity and photon spectral index of flat spectrum radio quasar (FSRQ) type
blazars, using non-parametric methods to obtain the evolutions and
distributions directly from the data. The sample we use for analysis consists
of almost all FSRQs observed with a greater than approximately 7 sigma
detection threshold in the first year catalog of the Fermi Gamma-ray Space
Telescope's Large Area Telescope, with redshfits as determined from optical
spectroscopy by Shaw et al. We find that FSQRs undergo rapid gamma-ray
luminosity evolution, but negligible photon index evolution, with redshift.
With these evolutions accounted for we determine the density evolution and
luminosity function of FSRQs, and calculate their total contribution to the
extragalactic gamma-ray background radiation, resolved and unresolved, which is
found to be 16(+10/-4)%, in agreement with previous studies.Comment: 9 pages, 10 figures, Accepted to Ap
The X-ray Luminosity Function Evolution of Quasars and the Correlation Between the X-ray and Ultraviolet Luminosities
We explore the evolution of the X-ray luminosity function of quasars and the
intrinsic correlation between the X-ray and 2500\AA ultraviolet
luminosities, utilizing techniques verified in previous works and a sample of
over 4000 quasars detected with Chandra and XMM-Newton in the range . We
find that quasars have undergone significantly less evolution with redshift in
their total X-ray luminosity than in other wavebands. We then determine that
the best fit intrinsic power law correlation between the X-ray and ultraviolet
luminosities, of the form , is
0.03, and we derive the luminosity function and density
evolution in the X-ray band. We discuss the implications of these results for
models of quasar systems.Comment: 9 pages, 7 figures, updated to version published in Ap
Flux and Photon Spectral Index Distributions of Fermi-LAT Blazars and Contribution to the Extragalactic Gamma-Ray Background
We present a determination of the distributions of the photon spectral index and gamma-ray fluxâthe so-called log Nâlog S relationâfor the 352 blazars detected with a greater than approximately 7Ï detection threshold and located above ±20⊠Galactic latitude by the Large Area Telescope of the Fermi Gamma-ray Space Telescope in its first year catalog. Because the flux detection threshold depends on the photon index, the observed raw distributions do not provide the true log Nâlog S counts or the true distribution of the photon index. We use the non-parametric methods developed by Efron and Petrosian to reconstruct the intrinsic distributions from the observed ones which account for the data truncations introduced by observational bias and includes the effects of the possible correlation between the two variables. We demonstrate the robustness of our procedures using a simulated data set of blazars and then apply these to the real data and find that for the population as a whole the intrinsic flux distribution can be represented by a broken power law with high and low indices of â2.37 ± 0.13 and â1.70 ± 0.26, respectively, and the intrinsic photon index distribution can be represented by a Gaussian with mean of 2.41±0.13 and width of 0.25± 0.03. We also find the intrinsic distributions for the sub-populations of BL Lac and flat spectrum radio quasar type blazars separately. We then calculate the contribution of Fermi blazars to the diffuse extragalactic gamma-ray background radiation. Under the assumption that the flux distribution of blazars continues to arbitrarily low fluxes, we calculate the best-fit contribution of all blazars to the total extragalactic gamma-ray output to be 60%, with a large uncertainty
Luminosity-Luminosity Correlations in Flux-Limited Multiwavelength Data
We explore the general question of correlations among different waveband luminosities in a flux-limited multiband observational data set. Such correlations, often observed for astronomical sources, may be either intrinsic or induced by the redshift evolution of the luminosities and the data truncation due to the flux limits. We first address this question analytically. We then use simulated flux-limited data with three different known intrinsic luminosity correlations and prescribed luminosity functions and evolution similar to the ones expected for quasars. We explore how the intrinsic nature of luminosity correlations can be deduced, including exploring the efficacy of partial correlation analysis with redshift binning in determining whether luminosity correlations are intrinsic and finding the form of the intrinsic correlation. By applying methods that we have developed in recent works, we show that we can recover the true cosmological evolution of the luminosity functions and the intrinsic correlations between the luminosities. Finally, we demonstrate the methods for determining intrinsic luminosity correlations on actual observed samples of quasars with mid-infrared, radio, and optical fluxes and redshifts, finding that the luminosityâ luminosity correlation is significantly stronger between mid-infrared and optical than that between radio and optical luminosities, supporting the canonical jet-launching and heating model of active galaxies
Waveband Luminosity Correlations in Flux-Limited Multiwavelength Data
We explore the general question of correlations among different waveband luminosities in a flux-limited multiband observational data set. Such correlations, often observed for astronomical sources, may be either intrinsic or induced by the redshift evolution of the luminosities and the data truncation due to the flux limits. We first address this question analytically. We then use simulated flux-limited data with three different known intrinsic luminosity correlations and prescribed luminosity functions and evolution similar to the ones expected for quasars. We explore how the intrinsic nature of luminosity correlations can be deduced, including exploring the efficacy of partial correlation analysis with redshift binning in determining whether luminosity correlations are intrinsic and finding the form of the intrinsic correlation. By applying methods that we have developed in recent works, we show that we can recover the true cosmological evolution of the luminosity functions and the intrinsic correlations between the luminosities. Finally, we demonstrate the methods for determining intrinsic luminosity correlations on actual observed samples of quasars with mid-infrared, radio, and optical fluxes and redshifts, finding that the luminosity-luminosity correlation is significantly stronger between mid-infrared and optical than that between radio and optical luminosities, supporting the canonical jet-launching and heating model of active galaxies
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The Radio and Optical Luminosity Evolution of Quasars II -- The SDSS Sample
We determine the radio and optical luminosity evolutions and the true distribution of the radio-loudness parameter R, defined as the ratio of the radio to optical luminosity, for a set of more than 5000 quasars combining Sloan Digital Sky Survey optical and Faint Images of the Radio Sky at Twenty cm (FIRST) radio data. We apply the method of Efron and Petrosian to access the intrinsic distribution parameters, taking into account the truncations and correlations inherent in the data. We find that the population exhibits strong positive evolution with redshift in both wavebands, with somewhat greater radio evolution than optical. With the luminosity evolutions accounted for, we determine the density evolutions and local radio and optical luminosity functions. The intrinsic distribution of the radio-loudness parameter R is found to be quite different from the observed one and is smooth with no evidence of a bimodality in radio loudness for logâR â„ â1. The results we find are in general agreement with the previous analysis of Singal et al., which used POSS-I optical and FIRST radio data
On the Radio and Optical Luminosity Evolution of Quasars II - The SDSS Sample
We determine the radio and optical luminosity evolutions and the true
distribution of the radio loudness parameter R, defined as the ratio of the
radio to optical luminosity, for a set of more than 5000 quasars combining SDSS
optical and FIRST radio data. We apply the method of Efron and Petrosian to
access the intrinsic distribution parameters, taking into account the
truncations and correlations inherent in the data. We find that the population
exhibits strong positive evolution with redshift in both wavebands, with
somewhat greater radio evolution than optical. With the luminosity evolutions
accounted for, we determine the density evolutions and local radio and optical
luminosity functions. The intrinsic distribution of the radio loudness
parameter R is found to be quite different than the observed one, and is smooth
with no evidence of a bi-modality in radio loudness. The results we find are in
general agreement with the previous analysis of Singal et al. 2011 which used
POSS-I optical and FIRST radio data.Comment: 16 pages, 17 figures, 1 table. Updated to journal version. arXiv
admin note: substantial text overlap with arXiv:1101.293
HUBUNGAN ANTARA PENGETAHUAN, SIKAP DAN PENDAPATAN DENGAN PEMANFAATAN PUSKESMAS OLEH MASYARAKAT DESA KIMA BAJO KECAMATAN WORI
Pengetahuan tentang puskesmas akan mempengaruhi perilaku masyarakat dalam pemanfaatan pelayanan puskesmas. Pengetahuan sangat penting perannya karena dengan adanya pengetahuan yang dimiliki masyarakat maka akan terbentuk sikap yang akan diikuti dengan tindakan memilih pelayanan kesehatan yang baik. Tujuan penelitian ini yaitu menganalisis hubungan pengetahuan, sikap dan pendapatan dengan pemanfaatan puskesmas oleh masyarakat Desa Kima Bajo Kecamatan Wori. Penelitian ini menggunakan metode survey analitik dengan pendekatan cross sectional. Lokasi penelitian dilaksanakan di Desa Kima Bajo pada bulan September â Oktober 2018. Populasi berjumlah 267 keluarga, sampel berjumlah 160 responden. Pengambilan sampel menggunakan teknik non probability sampling dengan menggunakan teknik pengambilan sampel dengan cara kuota sampel. Alat ukur yang digunakan adalah kuesioner. Analisis data menggunakan uji Chi-Square dan Fisher Exact test dengan nilai α = 0,05. Hasil penelitian terdapat hubungan antara pengetahuan dan sikap dengan pemanfaatan puskesmas dan tidak terdapat hubungan antara pendapatan keluarga dengan pemanfaatan puskesmas di Desa Kima Bajo Kecamatan Wori.Kesimpulan terdapat hubungan antara pengetahuan dan sikap dengan pemanfaatan puskesmas, tidak terdapat hubungan antara pendapatan keluarga dengan pemanfaatan puskesmas di Desa Kima Bajo Kecamatan Wori.Saran untuk masyarakat diharapkan untuk terus memanfaatkan secara maksimal fungsi dari puskesmas serta memiliki kepedulian dan partisipasi aktif disaat ada kegiatan dari pihak puskesmas. Kata kunci: Pengetahuan, sikap, pendapatan keluarga, pemanfaatan puskesmas  ABSTRACTKnowledge of puskesmas will influence people's behavior in utilizing puskesmas services. Knowledge is very important because the existence of knowledge owned by the community will form an attitude that will be followed by the act of choosing good health services. The purpose of this study was to analyze the relationship of knowledge, attitudes and income with the use of health centers by the community of Kima Bajo Village, Wori District. This study uses an analytical survey method with a cross sectional approach. The location of the study was conducted in Kima Bajo Village in September - October 2018. The population was 267 families, a sample of 160 respondents. Sampling uses non probability sampling techniques by using sampling techniques by means of sample quotas. The measuring instrument used is a questionnaire. Data analysis using Chi-Square test and Fisher Exact test with a value of α = 0.05. The results of the study showed that there was a relationship between knowledge and attitudes with the use of puskesmas and there was no relationship between family income and the use of puskesmas in Kima Bajo Village, Wori District. Kima Bajo Wori Subdistrict. Suggestions for the community are expected to continue to make maximum use of the functions of the puskesmas and have care and active participation when there are activities from the puskesmas.  Keywords: Knowledge, attitudes, family income, utilization of public health cente
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