1998A&A...329...74D

Query : 1998A&A...329...74D

1998A&A...329...74D - Astronomy and Astrophysics, volume 32974-80 (1998/1-1)

X-ray emission from dark clusters of MACHOs.

DE PAOLIS F., INGROSSO G., JETZER P. and RONCADELLI M.

Abstract (from CDS):

MACHOs (Massive Astrophysical Compact Halo Objects) - as discovered by microlensing experiments towards the LMC - provide a natural explanation for the galactic halo dark matter. A realistic possibility is that MACHOs are brown dwarfs of mass ∼0.1M_☉. Various arguments suggest that brown dwarfs should have a coronal X-ray emission of ∼10²⁷erg/s. As MACHOs are presumably clumped into dark clusters (DCs), each DC is expected to have a total X-ray luminosity of ∼10²⁹-10³²erg/s. We discuss the possibility that dark clusters contribute to the diffuse X-ray background (XRB) or show up as discrete sources in very deep field X-ray satellite observations. Moreover, from the observed diffuse XRB we infer that the amount of virialized diffuse gas present in the galactic halo can at most make up 5% of the halo dark matter.

Abstract Copyright: ∼

Journal keyword(s): dark matter - the halo of the Galaxy - brown dwarfs - X-rays: general

Simbad objects: 1

View the references in ADS

Number of rows : 1

N	Identifier	Otype	ICRS (J2000) RA	ICRS (J2000) DEC	Mag U	Mag B	Mag V	Mag R	Mag I	Sp type	#ref 1850 - 2026	#notes
1	VB 8	LM*	16 55 35.2557374336	-08 23 40.753073075		18.7	16.916	14.566	12.24	M7Ve	457	0

Query : 1998A&A...329...74D

Basic data :

VB 8 -- Low-mass Star

* (2014ApJ,CNS5,...), PM* (2013MNRAS,LHS,...), ** (CCDM,WDS), Er* (1999A&AS,[GKL99]), NIR (DENIS,2MASS), LM* (2019ApJ), X (EXO), Rad ([B2006]), MIR (WISEA), Opt (SDSS)

16 55 35.2557374336 -08 23 40.753073075 (Optical) [ 0.0448 0.0223 90 ] A 2020yCat.1350....0G

16 52 54.8174058712 -08 18 13.695295061 [ 0.0448 0.0223 90 ]

011.0082579251619 +21.0866551096272 [ 0.0448 0.0223 90 ]

-813.038 -870.609 [0.063 0.044 90] A 2020yCat.1350....0G

V(km/s) 15.68 [0.0436] / z(spectroscopic) 0.000052 [0.000000] / cz 15.68 [0.04] (Opt) A 2018MNRAS.475.1960F

153.9659 [0.0570] A 2020yCat.1350....0G

M7Ve C 2004AJ....128.2460H

B 18.7 [~] E ~

V 16.916 [0.057] D 2005AJ....130..337C

R 14.566 [0.012] D 2005AJ....130..337C

G 13.813289 [0.002813] C 2020yCat.1350....0G

I 12.24 [0.04] C 2005yCat.2263....0D

J 9.776 [0.029] C 2003yCat.2246....0C

H 9.201 [0.024] C 2003yCat.2246....0C

K 8.816 [0.023] C 2003yCat.2246....0C

u (AB) 19.26 [0.03] C 2009ApJS..182..543A

g (AB) 17.716 [0.005] C 2009ApJS..182..543A

r (AB) 16.020 [0.004] C 2009ApJS..182..543A

i (AB) 16.730 [0.015] C 2009ApJS..182..543A

z (AB) 11.749 [0.003] C 2009ApJS..182..543A

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`LHS 429`	`Karmn J16555-083`	`SDSS J165534.95-082345.5`	`WISEA J165534.68-082349.7`
`CCDM J16555-0820D`	`2MASS J16553529-0823401`	`TIC 181609153`	`Zkh 235`
`CNS5 4137`	`NLTT 43802`	`UCAC3 164-149688`	`[B2006] J165535.3-082340`
`CSI-08-16529`	`8pc 153.96C`	`UCAC4 409-067034`	`[GKL99] 336`
`DENIS J165535.4-082337`	`PM 16529-0818`	`USNO 869`	`[RHG95] 2663`
`EXO 1652.8-0818`	`PM J16555-0823`	`VB 8`	`Gaia DR3 4339417394313320192`
`GJ 644 C`	`PMSC 16501-0809D`	`WDS J16555-0820F`	`Gaia DR2 4339417394313320192`

References (457 between 1850 and 2026) (Total 457)
Simbad bibliographic survey began in 1850 for stars (at least bright stars) and in 1983 for all other objects (outside the solar system).

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Archive data at HEASARC - High-Energy Astrophysics Science Archive Research Center

Data at NED - NASA/IPAC Extragalactic Database : VB 8

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`LHS 429`	`CCDM J16555-0820D`	`DENIS J165535.4-082337`	`GJ 644 C`	`2MASS J16553529-0823401`
`NLTT 43802`	`SDSS J165534.95-082345.5`	`UCAC3 164-149688`	`UCAC4 409-067034`	`WDS J16555-0820F`
`WISEA J165534.68-082349.7`	`[GKL99] 336`	`Gaia DR3 4339417394313320192`	`Gaia DR2 4339417394313320192`

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