Data di Pubblicazione:
2013
Abstract:
Context. About half of the baryons of the Universe are expected to be in
the form of filaments of hot and low-density intergalactic medium. Most
of these baryons remain undetected even by the most advanced X-ray
observatories, which are limited in sensitivity to the diffuse
low-density medium.
Aims: The Planck satellite has provided
hundreds of detections of the hot gas in clusters of galaxies via the
thermal Sunyaev-Zel'dovich (tSZ) effect and is an ideal instrument for
studying extended low-density media through the tSZ effect. In this
paper we use the Planck data to search for signatures of a fraction of
these missing baryons between pairs of galaxy clusters.
Methods:
Cluster pairs are good candidates for searching for the hotter and
denser phase of the intergalactic medium (which is more easily observed
through the SZ effect). Using an X-ray catalogue of clusters and the
Planck data, we selected physical pairs of clusters as candidates. Using
the Planck data, we constructed a local map of the tSZ effect centred on
each pair of galaxy clusters. ROSAT data were used to construct X-ray
maps of these pairs. After modelling and subtracting the tSZ effect and
X-ray emission for each cluster in the pair, we studied the residuals on
both the SZ and X-ray maps.
Results: For the merging cluster pair
A399-A401 we observe a significant tSZ effect signal in the intercluster
region beyond the virial radii of the clusters. A joint X-ray SZ
analysis allows us to constrain the temperature and density of this
intercluster medium. We obtain a temperature of kT = 7.1 � 0.9
keV (consistent with previous estimates) and a baryon density of (3.7
� 0.2) � 10-4 cm-3.
Conclusions: The Planck satellite mission has provided the first SZ
detection of the hot and diffuse intercluster gas.
the form of filaments of hot and low-density intergalactic medium. Most
of these baryons remain undetected even by the most advanced X-ray
observatories, which are limited in sensitivity to the diffuse
low-density medium.
Aims: The Planck satellite has provided
hundreds of detections of the hot gas in clusters of galaxies via the
thermal Sunyaev-Zel'dovich (tSZ) effect and is an ideal instrument for
studying extended low-density media through the tSZ effect. In this
paper we use the Planck data to search for signatures of a fraction of
these missing baryons between pairs of galaxy clusters.
Methods:
Cluster pairs are good candidates for searching for the hotter and
denser phase of the intergalactic medium (which is more easily observed
through the SZ effect). Using an X-ray catalogue of clusters and the
Planck data, we selected physical pairs of clusters as candidates. Using
the Planck data, we constructed a local map of the tSZ effect centred on
each pair of galaxy clusters. ROSAT data were used to construct X-ray
maps of these pairs. After modelling and subtracting the tSZ effect and
X-ray emission for each cluster in the pair, we studied the residuals on
both the SZ and X-ray maps.
Results: For the merging cluster pair
A399-A401 we observe a significant tSZ effect signal in the intercluster
region beyond the virial radii of the clusters. A joint X-ray SZ
analysis allows us to constrain the temperature and density of this
intercluster medium. We obtain a temperature of kT = 7.1 � 0.9
keV (consistent with previous estimates) and a baryon density of (3.7
� 0.2) � 10-4 cm-3.
Conclusions: The Planck satellite mission has provided the first SZ
detection of the hot and diffuse intercluster gas.
Tipologia CRIS:
1.1 Articolo in rivista
Keywords:
galaxies: clusters: general; large-scale structure of Universe
Elenco autori:
P., Collaboration; P. A., R.; N., Aghanim; M., Arnaud; M., Ashdown; F., Atrio Barandela; J., Aumont; C., Baccigalupi; A., Balbi; A. J., Banday; R. B., Barreiro; J. G., Bartlett; K., Benabed; A., Beno�t; J., Bernard; M., Bersanelli; R., Bhatia; I., Bikmaev; H., B�hringer; A., Bonaldi; J. R., Bond; J., Borrill; F. R., Bouchet; H., Bourdin; R., Burenin; C., Burigana; P., Cabella; J., Cardoso; G., Castex; A., Catalano; L., Cay�n; A., Chamballu; R., Chary; L., Chiang; G., Chon; P. R., Christensen; D. L., Clements; S., Colafrancesco; L. P., L.; B., Comis; A., Coulais; B. P., Crill; F., Cuttaia; L., Danese; R. J., Davis; P. d., Bernardis; G. d., Gasperis; G. d., Zotti; J., Delabrouille; J., D�mocl�s; F., D�sert; J. M., Diego; K., Dolag; H., Dole; S., Donzelli; O., Dor�; U., D�rl; M., Douspis; X., Dupac; G., Efstathiou; T. A., En�lin; H. K., Eriksen; F., Finelli; I., Flores Cacho; O., Forni; M., Frailis; E., Franceschi; M., Frommert; K., Ganga; T., G�nova Santos; M., Giard; M., Gilfanov; Y., Giraud H�raud; J., Gonz�lez Nuevo; K. M., G�rski; A., Gregorio; A., Gruppuso; F. K., Hansen; D., Harrison; A., Hempel; S., Henrot Versill�; C., Hern�ndez Monteagudo; D., Herranz; S. R., Hildebrandt; E., Hivon; M., Hobson; W. A., Holmes; W., Hovest; G., Hurier; T. R., Jaffe; A. H., Jaffe; T., Jagemann; W. C., Jones; M., Juvela; I., Khamitov; T. S., Kisner; R., Kneissl; J., Knoche; L., Knox; M., Kunz; H., Kurki Suonio; G., Lagache; J., Lamarre; A., Lasenby; C. R., Lawrence; M. L., Jeune; R., Leonardi; P. B., Lilje; M., Linden V�rnle; M., L�pez Caniego; P. M., Lubin; G., Luzzi; J. F., Mac�as P�rez; B., Maffei; D., Maino; N., Mandolesi; M., Maris; F., Marleau; D. J., Marshall; E., Mart�nez Gonz�lez; S., Masi; M., Massardi; S., Matarrese; F., Matthai; P., Mazzotta; S., Mei; A., Melchiorri; J., Melin; L., Mendes; A., Mennella; S., Mitra; M., Miville Desch�nes; A., Moneti; L., Montier; G., Morgante; D., Munshi; J. A., Murphy; P., Naselsky; F., Nati; P., Natoli; H. U., N�rgaard Nielsen; F., Noviello; D., Novikov; I., Novikov; S., Osborne; F., Pajot; D., Paoletti; F., Pasian; G., Patanchon; O., Perdereau; L., Perotto; F., Perrotta; F., Piacentini; M., Piat; E., Pierpaoli; R., Piffaretti; S., Plaszczynski; E., Pointecouteau; G., Polenta; N., Ponthieu; L., Popa; T., Poutanen; G. W., Pratt; S., Prunet; J., Puget; J. P., Rachen; R., Rebolo; M., Reinecke; M., Remazeilles; C., Renault; S., Ricciardi; T., Riller; I., Ristorcelli; G., Rocha; M., Roman; C., Rosset; M., Rossetti; Mart�n, J. A. Rubi�o.; B., Rusholme; M., Sandri; G., Savini; B. M., Schaefer; D., Scott; G. F., Smoot; J., Starck; R., Sudiwala; R., Sunyaev; D., Sutton; A., Suur Uski; J., Sygnet; J. A., Tauber; Terenzi, Luca; L., Toffolatti; M., Tomasi; M., Tristram; M., Tucci; L., Valenziano; B. V., Tent; P., Vielva; F., Villa; N., Vittorio; L. A., Wade; B. D., Wandelt; N., Welikala; S. D., M.; D., Yvon; A., Zacchei; A., Zonca
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